A105733 Numbers n such that A105658(2n-1) != 2n-1 and A105658(2n) != n.

12, 13, 21, 22, 25, 27, 28, 29, 32, 42, 43, 50, 52, 54, 62, 64, 66, 70, 72, 73, 76, 81, 82, 85, 87, 90, 91, 92, 96, 99, 102, 103, 106, 112, 117, 120, 122, 123, 126, 129, 131, 132, 135, 140, 142, 144, 147, 152, 154, 155, 158, 159, 162, 169

Offset

1,1

Links

Table of n, a(n) for n=1..54.

Formula

A105658(n) = Product_{i=1..n} i^i / denominator( sum_{j=1..n} j(j+1)/2 / product_{k=0..i-1} j!/k!) ).

Mathematica

f[n_] := f[n] = Product[i^i, {i, n}]/Denominator[Sum[j(j + 1)/2/(Product[j!/k!, {k, 0, j - 1}]), {j, n}]]; Select[ Range[125], f[2# - 1] != 2# - 1 && f[2# ] != # &]

Crossrefs

Cf. A105658, A105731, A105732, A105769.

Sequence in context: A298591 A225102 A057488 * A035123 A140212 A123132

Adjacent sequences: A105730 A105731 A105732 * A105734 A105735 A105736

Keyword

nonn

Author

Jess E. Boling (tdbpeekitup(AT)yahoo.com) and Robert G. Wilson v, Apr 18 2005

Status

approved