34522domain: NAppears in sequencesSmallest k such that k^2+1 is divisible by A002144(n)^4.at n=3A145297Sum of cousin primes < 10^n.at n=2A152127a(n) is the smallest number such that a(n)^2 + 1 is divisible by 29^n.at n=4A218712a(n) = n*(n^2 + 3)/2.at n=41A229183