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A105732 Even numbers n such that A105658(n) != n/2. 3
16, 24, 26, 32, 40, 42, 44, 50, 54, 56, 58, 64, 84, 86, 96, 100, 102, 104, 106, 108, 110, 124, 128, 132, 136, 140, 144, 146, 148, 152, 156, 162, 164, 168, 170, 172, 174, 180, 182, 184, 186, 188, 192, 198, 204, 206, 212, 214, 224, 226, 228, 234, 236, 240, 242 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Table of n, a(n) for n=1..55.

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[2, 242, 2], 2f[ # ] != # &]

CROSSREFS

Cf. A105658, A105731, A105733, A105769.

Sequence in context: A325480 A205193 A052058 * A339328 A337378 A166319

Adjacent sequences: A105729 A105730 A105731 * A105733 A105734 A105735

KEYWORD

nonn

AUTHOR

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

STATUS

approved

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Last modified March 20 05:51 EDT 2023. Contains 361359 sequences. (Running on oeis4.)