A260931 a(n) = A260930(n)/6 for n > 2.

1, 1, 1, 2, 1, 1, 2, 4, 3, 1, 1, 1, 1, 4, 4, 8, 1, 2, 1, 1, 1, 3, 4, 1, 1, 2, 4, 1, 2, 1, 1, 2, 5, 1, 1, 2, 1, 1, 4, 4, 2, 6, 1, 1, 2, 5, 1, 7, 4, 1, 3, 2, 7, 4, 5, 2, 3, 5, 3, 2, 1, 1, 4, 4, 2, 2, 5, 4, 6, 7, 3, 2, 6, 5, 1, 1, 2, 1, 1, 11, 3, 7, 9, 2, 10, 2, 5

Offset

3,4

Links

Table of n, a(n) for n=3..89.

Example

a(6)=2 because A260930(6)/6 = 12/2 = 2.

Mathematica

Differences[Select[Range[1500], PrimeQ[2 + (#+1)^2] &, 100]]/6

Crossrefs

Cf. A067201, A260930.

Sequence in context: A023504 A157905 A356718 * A293819 A027113 A096470

Adjacent sequences: A260928 A260929 A260930 * A260932 A260933 A260934

Keyword

nonn,easy

Author

Michel Lagneau, Aug 04 2015

Status

approved