A078504 a(n) = binomial(sigma(n+1), sigma(n)).

3, 4, 35, 0, 924, 0, 6435, 0, 8568, 0, 30421755, 0, 1961256, 1, 2629575, 0, 62359143990, 0, 513791607420, 0, 58905, 0, 36052387482172425, 0, 4280561376, 0, 41648951840265, 0, 164307576757973059488, 0, 916312070471295267, 0, 25827165

Offset

1,1

Links

Table of n, a(n) for n=1..33.

Mathematica

Table[Binomial[DivisorSigma[1, i + 1], DivisorSigma[1, i]], {i, 1, 50}]
Binomial[#[[2]], #[[1]]]&/@Partition[DivisorSigma[1, Range[40]], 2, 1] (* Harvey P. Dale, Apr 15 2025 *)

Crossrefs

Cf. A000203.

Sequence in context: A387566 A025140 A246015 * A066090 A251259 A042891

Adjacent sequences: A078501 A078502 A078503 * A078505 A078506 A078507

Keyword

nonn

Author

Joseph L. Pe, Jan 05 2003

Status

approved