89755domain: NAppears in sequencesTruncated tetrahedral numbers: a(n) = (1/6)*(n+1)*(23*n^2 + 19*n + 6).at n=28A005906E.g.f.: exp(x*exp(x) + 1/2*x^2*exp(x)^2 + 1/4*x^4*exp(x)^4).at n=7A060907Number of endofunctions f on [n] such that f^9(i) = f(i) for all i in [n].at n=7A245505a(n) = n*(n+1)*(22*n-19)/6.at n=29A256716