This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A124043 #4 Oct 06 2016 12:31:58 %S A124043 1,0,435,90944,40563765,32659846104,43036380310735,86514409614060000, %T A124043 251739515511526387401,1017865281673593548065520, %U A124043 5534999211214597734889370091,39411238922605740572075832485280 %N A124043 Number of permutations of n distinct letters (ABCD...) each of which appears thrice with three fixed points. %e A124043 1 %e A124043 0, 0, 0, "1" %e A124043 1, 0, 9, "0", 9, 0, 1 %e A124043 56, 216, 378, "435", 324, 189, 54", 27, 0, 1 %e A124043 13833, 49464, 84510, "90944", 69039, 38448, 16476, 5184, 1431, 216, 54, 0, 1 %e A124043 6699824, 23123880, 38358540, "40563765", 30573900, 17399178, 7723640, 2729295, 776520, 180100, 33372, 5355, 540, 90, 0, 1 %e A124043 etc... %p A124043 p := (x, k)->k!^2*sum(x^j/((k-j)!^2*j!), j=0..k); R := (x, n, k)->p(x, k)^n; f := (t, n, k)->sum(coeff(R(x, n, k), x, j)*(t-1)^j*(n*k-j)!, j=0..n*k); for n from 0 to 6 do seq(coeff(f(t, n, 3), t, m)/3!^n, m=0..3*n); od; %Y A124043 Cf. A059058, A027468, A059073, A000459. %K A124043 nonn %O A124043 0,3 %A A124043 _Zerinvary Lajos_, Nov 02 2006