A120288 Numerator of 1/n^4 + 2/(n-1)^4 + 3/(n-2)^4 +...+ (n-1)/2^4 + n.

1, 33, 2033, 87425, 11440331, 82653347, 58026230977, 472474237481, 38806560342253, 431701520479427, 579954645879123307, 7598398013722878661, 16804804720323979155637, 16901141697896969645401

Offset

1,2

Comments

p^2 divides a(p-1) for prime p>3. p divides a(p-2) for prime p>5.

Links

Table of n, a(n) for n=1..14.

Formula

a(n) = numerator[Sum[Sum[1/i^4,{i,1,k}],{k,1,n}]].

Mathematica

Numerator[Table[Sum[Sum[1/i^4, {i, 1, k}], {k, 1, n}], {n, 1, 20}]]

Crossrefs

Cf. A001008, A007406, A007407, A007408, A007410.

Sequence in context: A284221 A264170 A180920 * A284112 A099370 A267672

Adjacent sequences: A120285 A120286 A120287 * A120289 A120290 A120291

Keyword

frac,nonn

Author

Alexander Adamchuk, Jul 07 2006

Status

approved