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

Author

Alexander Adamchuk, Jul 07 2006

Keywords

• frac
• nonn

Comments

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

Crossrefs

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

Programs

Mathematica

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

Formula

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