%I #8 Apr 27 2017 10:39:08

%S 2,5,11,47,137,167,317,461,761,977,1307,1787,2111,2711,3677,4457,5861,

%T 7247,7457,9011,10211,13397,15761,17987,22511,23627,43607,45677,54437,

%U 56747,58511,61511,63347,65837,66467,79697,82487,88211,90407,93377,97157,108947

%N Primes equal to a centered triangular number plus 1.

%H Colin Barker, <a href="/A285809/b285809.txt">Table of n, a(n) for n = 1..1000</a>

%o (PARI) cpg(m, n) = m*n*(n-1)/2+1 \\ n-th centered m-gonal number

%o maxk=600; L=List(); for(k=1, maxk, if(isprime(p=cpg(3, k) + 1), listput(L, p))); Vec(L)

%Y Cf. A000040, A005448, A285810, A285811, A285812.

%K nonn

%O 1,1

%A _Colin Barker_, Apr 27 2017