1,2

a(4) = 10 = sum of row 4 terms of triangle A137629: (7 + 2 + 0 + 1).

Cf. A026794, A137629.

Sequence in context: A001841 A008610 A078411 this_sequence A092269 A089483 A023602

Adjacent sequences: A137627 A137628 A137629 this_sequence A137631 A137632 A137633

nonn

Gary W. Adamson (qntmpkt(AT)yahoo.com), Jan 31 2008