A285812 - OEIS

%I #7 Apr 27 2017 10:23:24

%S 2,11,29,137,191,821,947,2081,2927,3917,5051,6329,11027,13367,14879,

%T 15401,17021,17579,21737,22367,24977,36857,39341,43661,47279,50087,

%U 58997,62129,66431,70877,95267,96581,106031,113051,117371,129287,130817,135461,156521

%N Primes equal to a centered 9-gonal number plus 1.

%H Colin Barker, <a href="/A285812/b285812.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(9, k) + 1), listput(L, p))); Vec(L)

%Y Cf. A000040, A060544, A285809, A285810, A285811.

%K nonn

%O 1,1

%A _Colin Barker_, Apr 27 2017