76655domain: NAppears in sequencesa(1) = 1; a(n) = a(n-1) + sigma(a(n-1)) where sigma(k) = sum of the divisors of k.at n=15A081973Irregular array where row n is the positive integers which divide the sum of all previous rows. a(1,1)=1.at n=47A119763Numbers k such that 3^k + 22 is prime.at n=27A219042