%I #7 Feb 01 2019 16:40:00

%S 1,16,40,73,115,163,220,284,358,435,520,610,706,812,924,1039,1164,

%T 1295,1424,1573,1716,1878,2033,2191,2367,2548,2730,2916,3108,3303,

%U 3513,3732,3946,4165,4397,4628,4858,5107,5357,5612,5883,6148,6415,6685,6961,7253

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

%e a(1)=1 because prime(1) > (6*0 + 1)^2;

%e a(2)=16 because prime(16) > (6*1+1)^2 > prime(15);

%e a(3)=40 because prime(40) > (6*2+1)^2 > prime(39).

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

%Y Cf. A016922.

%K nonn,easy

%O 1,2

%A _Juri-Stepan Gerasimov_, Mar 15 2010

%E Definition corrected by _Charles R Greathouse IV_, Mar 20 2010