A027143 a(n) = Sum_{k=0..2n-3} T(n,k) * T(n,k+3), with T given by A027113.

57, 486, 4117, 34760, 293086, 2471917, 20870169, 176467252, 1494672812, 12682766442, 107814252502, 918166760699, 7832993240285, 66936986352534, 572934789920969, 4911478255448828, 42165255645650628, 362494201554529232, 3120475613849051712, 26895832224848130557

Offset: 3

Author

Clark Kimberling

Keywords

• nonn

Crossrefs

Cf. A027113.

Extensions

More terms from Sean A. Irvine, Oct 23 2019