A049634 a(n) = T(n,n+2), array T as in A049627.

2, 6, 9, 15, 19, 29, 35, 47, 55, 71, 79, 101, 111, 131, 145, 169, 183, 217, 231, 261, 279, 313, 331, 373, 393, 431, 455, 501, 521, 579, 603, 653, 685, 729, 757, 817, 847, 907, 941, 1005, 1033, 1115, 1147, 1213, 1255, 1325, 1363, 1451, 1487, 1561, 1605, 1689

Offset

0,1

Links

Table of n, a(n) for n=0..51.

Prog

(PARI) T(n, k) = (n+1)*(k+1) - sum(i=0, n, sum(j=0, k, gcd(i, j)>1)); \\ A049627
a(n) = T(n, n+2); \\ Michel Marcus, Aug 06 2021

Crossrefs

Cf. A049627.

Sequence in context: A189760 A363373 A353083 * A120387 A325761 A176039

Adjacent sequences: A049631 A049632 A049633 * A049635 A049636 A049637

Keyword

nonn

Author

Clark Kimberling

Extensions

More terms from Sean A. Irvine, Aug 05 2021

Status

approved