A105731 Odd numbers n such that A105658(n) != n.

13, 17, 23, 25, 37, 41, 43, 47, 49, 53, 55, 57, 59, 61, 63, 65, 67, 69, 71, 75, 77, 81, 83, 85, 97, 99, 103, 107, 111, 117, 121, 123, 125, 127, 129, 131, 137, 139, 143, 145, 149, 151, 153, 157, 159, 161, 163, 169, 173, 177, 179, 181, 183, 189, 191, 193, 195, 197

Offset

1,1

Links

Table of n, a(n) for n=1..58.

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[1, 200, 2], f[ # ] != # &]

Crossrefs

Cf. A105658, A105732, A105733, A105769.

Sequence in context: A134257 A272078 A205722 * A060343 A080603 A179924

Adjacent sequences: A105728 A105729 A105730 * A105732 A105733 A105734

Keyword

nonn

Author

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

Status

approved