%I #12 Dec 23 2023 20:25:58

%S 361,451,551,781,1711,2101,2761,3781,4061,4351,5611,5951,7031,7801,

%T 8201,8611,9031,10351,10811,11281,11761,12751,13261,14311,15961,16531,

%U 17111,17701,21451,23461,26281,28501,29261,30031,30811,34861,35701,40951,41861,42781,45601,46561

%N Centered 10-gonal numbers which are products of two primes.

%e A062786(9) = 361 = 5 * 9 * (9-1) + 1 = 19 * 19.

%e A062786(10) = 451 = 5 * 10 * (10-1) + 1 = 11 * 41.

%e A062786(11) = 551 = 5 * 11 * (11-1) + 1 = 19 * 29.

%t Select[Table[5*n*(n-1) + 1, {n, 1, 100}], PrimeOmega[#] == 2 &] (* _Amiram Eldar_, Nov 30 2023 *)

%Y Intersection of A062786 and A001358.

%K nonn

%O 1,1

%A _Massimo Kofler_, Nov 30 2023