A089027 a(n) =1 if the prime gap A001223(n) is <=2, otherwise a(n)=n+1.

1, 1, 1, 5, 1, 7, 1, 9, 10, 1, 12, 13, 1, 15, 16, 17, 1, 19, 20, 1, 22, 23, 24, 25, 26, 1, 28, 1, 30, 31, 32, 33, 1, 35, 1, 37, 38, 39, 40, 41, 1, 43, 1, 45, 1, 47, 48, 49, 1, 51, 52, 1, 54, 55, 56, 57, 1, 59, 60, 1, 62, 63, 64, 1, 66, 67, 68, 69, 1, 71, 72, 73, 74, 75, 76, 77, 78, 79, 80

Offset

1,4

Links

Table of n, a(n) for n=1..79.

Mathematica

digits=200 a=Table[If[Prime[n]-Prime[n-1]>2, n, 1], {n, 2, digits}]

Crossrefs

Sequence in context: A265293 A348502 A340089 * A354432 A023890 A319684

Adjacent sequences: A089024 A089025 A089026 * A089028 A089029 A089030

Keyword

nonn

Author

Roger L. Bagula, Nov 12 2003

Status

approved