A173754 a(n)=m-k where x^2+x+41=m-th prime and x^2-x+41=k-th prime.

0, 1, 1, 1, 2, 2, 3, 2, 5, 2, 4, 4, 5, 3, 6, 6, 5, 4, 7, 6, 7, 7, 5, 7, 8, 9, 7, 7, 8, 9, 8, 10, 10, 8, 10, 10, 8, 9, 12, 11, 12, 10, 14, 14, 15, 15, 13, 12, 13, 13, 16, 16, 14, 17, 13, 14, 15, 17, 13, 20, 15, 15, 18, 18, 17, 18, 22, 14, 16, 25, 21, 20, 20, 24, 19, 25, 21, 22, 20, 24, 28

Offset

1,5

Links

Table of n, a(n) for n=1..81.

Example

a(1)=13-13=0 where 0^2+0+41=41=13th prime and 0^2-0+41=41=13th prime; a(2)=14-13=1 where 1^2+1+41=43=14th prime and 1^2-1+41=41=13th prime; a(3)=15-14=1 where 2^2+2+41=47=15th prime and 2^2-2+41=43=14th prime; a(4)=16-15=1 where 3^2+3+41=53=16th prime and 3^2-3+41=47=15th prime.

Crossrefs

Cf. A005846.

Sequence in context: A325339 A010846 A073023 * A180125 A342086 A272209

Adjacent sequences: A173751 A173752 A173753 * A173755 A173756 A173757

Keyword

nonn

Author

Juri-Stepan Gerasimov, Feb 23 2010

Extensions

a(7), a(11) etc. corrected and sequence extended by R. J. Mathar, Mar 01 2010

Status

approved