1,2
a(4) = 33 = sum of row 4 terms of triangle A131424: (6 + 7 + 9 + 11).
Cf. A131424, A131426, A127640, A000040.
Sequence in context: A045944 A038361 A172166 * A096941 A098404 A190970
Adjacent sequences: A131422 A131423 A131424 * A131426 A131427 A131428
nonn
Gary W. Adamson (qntmpkt(AT)yahoo.com), Jul 10 2007