A046948 Sizes of successive balls in E_8 lattice.

1, 241, 2401, 9121, 26641, 56881, 117361, 199921, 340321, 522001, 794161, 1113841, 1604401, 2131921, 2874961, 3721681, 4845121, 6024481, 7659601, 9306001, 11513521, 13825201, 16702321, 19622641, 23553841, 27334081

Offset

0,2

Links

Table of n, a(n) for n=0..25.

Formula

a(n) ~ 2 * Pi^4 * n^4 / 3. - Vaclav Kotesovec, Jan 14 2024

Prog

(PARI) B=1; th=[ 1 ]; bl=[ 1 ]; for (n=1, 10000, t1=divisors(n); t2=0; for (i=1, length(t1), t2=t2+t1[ i ]^3); t3=240*t2; th=concat(th, t3); B=B+t3; bl=concat(bl, B)); th; bl;

Crossrefs

Partial sums of A004009.

Sequence in context: A167739 A373708 A119596 * A220056 A165383 A006687

Adjacent sequences: A046945 A046946 A046947 * A046949 A046950 A046951

Keyword

nonn

Author

N. J. A. Sloane

Status

approved