A085931 Leading diagonal of A085930.

2, 4, 12, 17, 23, 39, 48, 58, 69, 95, 109, 124, 140, 157, 195, 215, 236, 258, 281, 305, 357, 384, 412, 441, 471, 502, 534, 602, 637, 673, 710, 748, 787, 827, 868, 954, 998, 1043, 1089, 1136, 1184, 1233, 1283, 1334, 1440, 1494, 1549, 1605, 1662, 1720, 1779

Offset: 1

Author

Jason Earls and Amarnath Murthy, Jul 14 2003

Keywords

• easy
• nonn

Links

• Gheorghe Coserea, Table of n, a(n) for n = 1..10000
• T. Forbes, Prime k-tuplets

Crossrefs

Cf. A085930.

Programs

PARI

a(n) = my(x = (sqrtint(1+8*n)-1)\2); (x+n)*(x+n+1)/2 - n;
vector(51, n, a(n))  \\ Gheorghe Coserea, Mar 25 2016

Extensions

Offset corrected by Gheorghe Coserea, Mar 25 2016