Can anyone post the block number of a block using merged mining ?

[Sergio_Demian_Lerner]

I want to analyze how a block with merged mining looks like. I've read that dumb transactions are used for merged mining, and that those transactions transfer 0 BTC from an address to a hash for the alternate chain block. But I've never actually seen such a transaction in a block.

Blockexplorer.com has a service to search for nonstandard transactions, but it is unavailable at this moment.

Can anyone post the block number of a block that has merged mining ? With the block number I can dump the block with the tools at Blockexplorer.com or blockchain.info.

Best regards,
Sergio.

[1715014673]

1715014673

[1715014673]

1715014673

[1715014673]

1715014673

[1715014673]

1715014673

[1715014673]

1715014673

[1715014673]

1715014673

[deepceleron]

All merge-mined:

http://ozco.in/content/block-history-namecoin

[Sergio_Demian_Lerner]

But I mean the Bitcoin blocks, not the Namecoin blocks. I want to find a Bitcoin block that mines for Bitcoin and Namecoin (indirectly).

[Stephen Gornick]

But I mean the Bitcoin blocks, not the Namecoin blocks. I want to find a Bitcoin block that mines for Bitcoin and Namecoin (indirectly).

A Bitcoin block that was used for merged mining of a namecoin block will include as its first transaction the hash of the namecoin block.  So looking at BlockExplorer:

Block 184,053 is one of these, I believe:
 - http://blockexplorer.com/b/184053

Click the link for Raw block:
 - http://blockexplorer.com/rawblock/000000000000080ce0b71e18041a3f39425695250748fb045c9645920b0c8dea

The coinbase includes the hash for namecoin block 60019 ( a7e5dd00502b4aa45a7a68540f654ebb11ad870882af0d77959a0fb6d8307b84 ):
 - http://explorer.dot-bit.org/b/60019

So Namecoin block 60,019 is merge mined against Bitcoin block 184,053.

Coincidentally, the previous namecoin block appears to have been merge mined against the previous Bitcoin block:
 - http://blockexplorer.com/b/184052
 - http://explorer.dot-bit.org/b/60018

But Bitcoin block 184,054 does not appear to have the namecoin hash but it does appear to have some additional hash, probably from some other alt chain.
 - http://blockexplorer.com/b/184054

Bitcoin block 184,057 does not appear to have any merged mining hashes:
 - http://blockexplorer.com/b/184057

[Sergio_Demian_Lerner]

Excellent info Stephen!

It's interesting that miners are using the coinbase field (coinbase scriptpub) to store all sorts of strings, such as the mining pool that mined the block (e.g. BitMinter). Also the /P2SH/ string is still there. Is it still necessary? The 15 Feb 2012 deadline for BIP 16 change has already past.

Is there any formal specification of the Bitcoin coinbase field for namecoin?
If not, then I'll have to check namecoin source code.

Best regards!