A172180 The absolute value of n-th prime of the form 3*n-+1 minus n-th nonprime of the form 3*n-+1.

1, 1, 1, 1, 1, 1, 1, 1, 4, 5, 9, 9, 9, 12, 15, 19, 17, 21, 22, 23, 27, 28, 33, 39, 39, 39, 42, 41, 43, 53, 55, 60, 59, 67, 66, 71, 75, 76, 81, 85, 86, 93, 93, 93, 93, 101, 111, 112, 113, 115, 120, 120, 129, 133, 138, 141, 141, 144, 147, 147, 153, 165, 168, 168, 171, 183, 185

Offset

1,9

Links

Table of n, a(n) for n=1..67.

Formula

a(n) = abs(A045344(n)-A171993(n)).

Example

a(1) = abs(2-1) = 1.
a(2) = abs(5-4) = 1.
a(3) = abs(7-8) = 1.
a(4) = abs(11-10) = 1.
a(5) = abs(13-14) = 1.
a(6) = abs(17-16) = 1.
a(7) = abs(19-20) = 1.
a(8) = abs(23-22) = 1.
a(9) = abs(29-25) = 4.

Crossrefs

Cf. A045344, A171993.

Sequence in context: A197268 A218505 A128891 * A193959 A093667 A243591

Adjacent sequences: A172177 A172178 A172179 * A172181 A172182 A172183

Keyword

nonn

Author

Juri-Stepan Gerasimov, Jan 28 2010

Extensions

Corrected (28 inserted, a third 39 inserted etc.) by R. J. Mathar, May 19 2010

Status

approved