A137424 a(n) = binomial(digsum(n), n mod digsum(n)).

1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 1, 4, 5, 20, 21, 8, 1, 10, 1, 1, 6, 10, 1, 35, 28, 1, 45, 330, 1, 4, 10, 20, 7, 56, 1, 120, 462, 220, 1, 5, 1, 7, 70, 1, 210, 165, 1, 286, 1, 20, 35, 56, 1, 252, 11, 220, 1716, 364, 1, 21, 28, 1, 210, 11, 924, 78, 91, 5005, 1, 8, 1, 120, 165, 220, 78

Offset

1,11

Links

Robert Israel, Table of n, a(n) for n = 1..10000

Maple

P:=proc(n) local a, k, i; for i from 1 by 1 to n do a:=0; k:=i; while k>0 do a:=a+(k mod 10); k:=trunc(k/10); od; k:=binomial(a, (i mod a)); print(k); od; end: P(101);

Mathematica

a[n_]:=Binomial[DigitSum[n], Mod[n, DigitSum[n]]]; Array[a, 76] (* Stefano Spezia, Dec 02 2025 *)

Crossrefs

Cf. A007953, A070635.

Sequence in context: A209337 A243004 A375156 * A394893 A083007 A309845

Adjacent sequences: A137421 A137422 A137423 * A137425 A137426 A137427

Keyword

easy,nonn,look

Author

Paolo P. Lava and Giorgio Balzarotti, Apr 17 2008

Extensions

Offset changed to 1 by Stefano Spezia, Dec 02 2025

Status

approved