65255domain: NAppears in sequencesTruncated square pyramid numbers: a(n) = Sum_{k = n..2*n} k^2.at n=30A050409Integers k such that 5*10^k + 51 is prime.at n=12A110983Numbers k whose binary expansion starts with the concatenation of the binary expansions of the run lengths in binary expansion of k.at n=40A348111