A174321 Index of the smallest prime greater than (6n+1)^2.

1, 16, 40, 73, 115, 163, 220, 284, 358, 435, 520, 610, 706, 812, 924, 1039, 1164, 1295, 1424, 1573, 1716, 1878, 2033, 2191, 2367, 2548, 2730, 2916, 3108, 3303, 3513, 3732, 3946, 4165, 4397, 4628, 4858, 5107, 5357, 5612, 5883, 6148, 6415, 6685, 6961, 7253

Offset

1,2

Links

Table of n, a(n) for n=1..46.

Example

a(1)=1 because prime(1) > (6*0 + 1)^2;
a(2)=16 because prime(16) > (6*1+1)^2 > prime(15);
a(3)=40 because prime(40) > (6*2+1)^2 > prime(39).

Maple

A174321 := proc(n) numtheory[pi](nextprime((6*n+1)^2)) ; end proc: seq(A174321(n), n=0..80) ; # R. J. Mathar, Mar 29 2010

Crossrefs

Cf. A016922.

Sequence in context: A247345 A332519 A177723 * A258258 A086046 A184030

Adjacent sequences: A174318 A174319 A174320 * A174322 A174323 A174324

Keyword

nonn,easy

Author

Juri-Stepan Gerasimov, Mar 15 2010

Extensions

Definition corrected by Charles R Greathouse IV, Mar 20 2010

Status

approved