A049628 a(n) = Sum_{i=0..n} T(i,n-i) where T is A049627.

1, 4, 8, 14, 22, 34, 48, 68, 92, 122, 156, 200, 248, 308, 374, 448, 530, 628, 732, 854, 984, 1126, 1278, 1452, 1634, 1836, 2050, 2282, 2526, 2798, 3078, 3388, 3714, 4060, 4422, 4808, 5206, 5640, 6092, 6568, 7060, 7592, 8136, 8722, 9328, 9958, 10610, 11308

Offset

0,2

Links

Table of n, a(n) for n=0..47.

Prog

(PARI) T(n, k) = (n+1)*(k+1) - sum(i=0, n, sum(j=0, k, gcd(i, j)>1)); \\ A049627
a(n) = sum(i=0, n, T(i, n-i)); \\ Michel Marcus, Aug 06 2021

Crossrefs

Cf. A049627.

Partial sums of A225531.

Sequence in context: A333700 A011897 A110895 * A063757 A193711 A079328

Adjacent sequences: A049625 A049626 A049627 * A049629 A049630 A049631

Keyword

nonn

Author

Clark Kimberling

Extensions

More terms from Sean A. Irvine, Aug 05 2021

Status

approved