113380261800domain: NAppears in sequencesBinomial coefficients C(2n, n-2).at n=18A002694Binomial coefficient C(40,n).at n=18A010956Binomial coefficient C(40,n).at n=22A010956a(n) = binomial(n,18).at n=22A010971a(n) = binomial(n,22).at n=18A010975a(n) = binomial(sigma(n), phi(n)).at n=26A064366