A108568 a(n) = prime(n) + prime(n+1) - 2n - 1.

2, 3, 5, 9, 13, 17, 21, 25, 33, 39, 45, 53, 57, 61, 69, 79, 85, 91, 99, 103, 109, 117, 125, 137, 147, 151, 155, 159, 163, 179, 195, 203, 209, 219, 229, 235, 245, 253, 261, 271, 277, 287, 297, 301, 305, 317, 339, 353, 357, 361, 369, 375, 385, 399, 409, 419, 425

Offset: 1

Author

Giovanni Teofilatto, Jul 05 2005

Keywords

• easy
• nonn

Crossrefs

Cf. A108562.

Programs

PARI

a(n) = prime(n) + prime(n+1) - 2*n - 1 \\ Michel Marcus, Jun 03 2013

Extensions

Extended by Ray Chandler, Jul 10 2005