130302domain: NAppears in sequencesa(n) = n^4 - n.at n=19A058895Number of permutations of length n which avoid the patterns 2134, 3421.at n=10A116706a(n) = prime(n)^4 - prime(n).at n=7A138401a(n) = 361*n^2 - 19.at n=18A158595Number of conjugacy classes in GL(n,19).at n=4A182609