A128266 a(n) = Sum_{m=1..n} gcd(s(n,m), S(n,m)), where s(n,m) is an unsigned Stirling number of the first kind and S(n,m) is a Stirling number of the second kind.

1, 2, 5, 9, 22, 68, 163, 136, 525, 14519, 3918, 5954, 26561, 23897, 875479, 464545, 303146, 1576515, 15328385, 1297494, 25992621, 92698823, 64096034, 31484634, 16667307085, 737157766, 397339059223, 115011291216, 30816653208, 4304179162

Offset

1,2

Links

Table of n, a(n) for n=1..30.

Maple

with(combinat): T:=(n, k)->gcd(abs(stirling1(n, k)), stirling2(n, k)): seq(add(T(n, k), k=1..n), n=1..35); # Emeric Deutsch, Feb 25 2007

Crossrefs

Sequence in context: A268651 A342556 A002935 * A374244 A088356 A246350

Adjacent sequences: A128263 A128264 A128265 * A128267 A128268 A128269

Keyword

nonn

Author

Leroy Quet, Feb 22 2007

Extensions

More terms from Emeric Deutsch, Feb 25 2007

Status

approved