A096869 Difference between the n-th repunit and the next prime.

1, 2, 2, 6, 2, 8, 40, 6, 2, 10, 2, 38, 28, 12, 118, 12, 8, 20, 60, 20, 46, 78, 6, 2, 102, 272, 80, 246, 6, 80, 102, 36, 116, 10, 36, 10, 238, 32, 20, 6, 78, 412, 88, 426, 118, 172, 48, 58, 112, 8, 56, 430, 90, 136, 240, 30, 140, 232, 162, 40, 226, 48, 116, 60, 690, 146, 210

Offset: 1

Author

Robert G. Wilson v, Jul 12 2004

Keywords

• nonn

Crossrefs

Cf. A096870.

Programs

Mathematica

NextPrim[n_] := Block[{k = n + 1}, While[ !PrimeQ[k], k++ ]; k]; Table[ NextPrim[(10^n - 1)/9] - (10^n - 1)/\ 9, {n, 70}]

Formula

a(n) = A096497(n) - A002275(n) = A096499(n) - A096870(n).