A105769 A105658(n)/k, k=n if n is odd, else k=n/2.

1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 11, 1, 1, 13, 55, 1, 1, 1, 1, 1, 175, 325, 13, 253, 1, 1, 1, 1, 1, 23, 1, 1, 1, 1, 5, 1, 1, 19, 11, 19, 5, 35, 1, 1, 629, 1, 253, 29, 1, 1, 29, 31, 43, 37, 5, 13, 43, 1, 1219, 1, 55, 5, 186599, 1, 72283, 1, 29, 1, 47, 1, 1, 1, 1711, 1, 25, 1, 1, 1, 67, 1

Offset

1,13

Comments

Records: 1,11,13,55,175,325,629,1219,186599,6298799,24804047515,..., which occur at: 1,13,16,17,23,24,47,61,65,180,337,...

Links

Table of n, a(n) for n=1..82.

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}]]; Table[ If[ OddQ[n], f[n]/n, 2f[n]/n], {n, 82}]

Crossrefs

Cf. A105658, A105731, A105732.

Sequence in context: A332499 A010192 A214326 * A157171 A143685 A168647

Adjacent sequences: A105766 A105767 A105768 * A105770 A105771 A105772

Keyword

nonn

Author

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

Status

approved