1,2

a(4) = 33 = sum of row 4 terms of triangle A131424: (6 + 7 + 9 + 11).

Cf. A131424, A131426, A127640, A000040.

Adjacent sequences: A131422 A131423 A131424 this_sequence A131426 A131427 A131428

Sequence in context: A132479 A045944 A038361 this_sequence A096941 A098404 A077415

nonn

Gary W. Adamson (qntmpkt(AT)yahoo.com), Jul 10 2007