234272domain: NAppears in sequencesSum of composite numbers up to n is palindromic.at n=15A057959a(0) = 0, a(n) = Sum_{0<d|n, n/d odd} d^4 for n > 0.at n=22A285989Sum of the 4th powers of the divisor complements of the odd proper divisors of n.at n=21A352050