A069876 a(1) = 1, a(2) = 2^2 + 3^2; a(n) = (k-n+1)^n + (k-n)^n + ....(k-1)^n + k^n, where k = n(n+1)/2.

1, 13, 405, 23058, 2078375, 271739011, 48574262275, 11373936899396, 3377498614484589, 1240006139651007925, 551449374186192949841, 292093390490112799117190, 181694111127303339553250275

Offset

1,2

Comments

Sum of next n n-th powers.

Links

Table of n, a(n) for n=1..13.

Example

a(1) = 1^1 = 1; a(2) = 2^2 + 3^2 = 13; a(3) = 4^3 + 5^3 + 6^3 = 405, a(4) = 7^4 + 8^4 + 9^4 + 10^4 = 23058.

Mathematica

i1 := n(n-1)/2+1; i2 := n(n-1)/2+n; Table[Sum[i^n, {i, i1, i2}], {n, 20}]

Crossrefs

Cf. A072474 (s=2), A075664 - A075670 (s=3-10), A075671 (s=n).

Sequence in context: A162446 A284824 A075672 * A126086 A055203 A088919

Adjacent sequences: A069873 A069874 A069875 * A069877 A069878 A069879

Keyword

nonn

Author

Amarnath Murthy, Apr 25 2002

Extensions

More terms from Larry Reeves (larryr(AT)acm.org) and Zak Seidov, Sep 24 2002

Status

approved