A025156 A prime number of consecutive composites follow n.

7, 8, 13, 14, 19, 20, 23, 25, 26, 31, 33, 34, 37, 38, 43, 44, 47, 49, 50, 53, 55, 56, 61, 63, 64, 67, 68, 73, 75, 76, 79, 80, 83, 85, 86, 89, 91, 93, 94, 97, 98, 103, 104, 109, 110, 113, 115, 119, 121, 123, 124, 127, 128, 131, 133, 134, 141, 143, 145

Offset

1,1

Links

T. D. Noe, Table of n, a(n) for n = 1..1000

C. K. Caldwell, Composite Numbers.

Example

a(1)=7 because 3 consecutive composites {8, 9 and 10} follow 7 and 3 is prime.

Mathematica

Transpose[Select[Table[{n, NextPrime[n]-n-1}, {n, 300}], PrimeQ[ Last[#]]&]][[1]] (* Harvey P. Dale, May 26 2011 *)

Crossrefs

Cf. A000040.

Sequence in context: A061905 A308887 A308833 * A228210 A045765 A118068

Adjacent sequences: A025153 A025154 A025155 * A025157 A025158 A025159

Keyword

easy,nice,nonn

Author

G. L. Honaker, Jr.

Extensions

More terms from Harvey P. Dale, May 26 2011

Status

approved