531522domain: NAppears in sequencesSums of two distinct powers of 9.at n=17A038487a(n) = Sum_{d|n, d=3 mod 4} d^4.at n=26A050455a(n) = Sum_{d|n, n/d=1 mod 4} d^4.at n=26A050463Sums of two powers of 9.at n=23A055260a(n) = n^4*sigma_8(n).at n=3A386788