A049633 a(n) = T(n,n+1), array T as in A049627.

2, 5, 8, 12, 18, 24, 32, 42, 52, 62, 76, 90, 106, 124, 138, 154, 178, 200, 224, 250, 270, 292, 324, 354, 382, 414, 444, 474, 514, 550, 588, 634, 670, 706, 746, 782, 830, 884, 926, 966, 1022, 1074, 1128, 1190, 1234, 1280, 1348, 1410, 1468, 1530, 1582, 1638

Offset: 0

Author

Clark Kimberling

Keywords

• nonn

Crossrefs

Cf. A049627.

Programs

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+1); \\ Michel Marcus, Aug 06 2021

Extensions

More terms from Sean A. Irvine, Aug 05 2021