cp's OEIS Frontend

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.

A366706 Number of permutations of length n avoiding the permutations 13452, 13542, 14253, 14352, 14532, 15243, 15342, 15432, 24153, and 25143.

Original entry on oeis.org

1, 1, 2, 6, 24, 110, 540, 2772, 14704, 79974, 443592, 2499596, 14268740, 82339972, 479549860, 2815097792, 16639456452, 98947148126, 591537712636, 3553227623724, 21434384242112, 129796819639908, 788724906697704, 4807951095533744, 29393378297989024
Offset: 0

Views

Author

Jay Pantone, Oct 17 2023

Keywords

Formula

G.f. satisfies the minimal polynomial (4*x-1)*F(x)^4+(-16*x+6)*F(x)^3+(x^2+24*x-13)*F(x)^2+(-16*x+12)*F(x)+4*x-4 = 0.
a(n) ~ sqrt((2 - 8*s + (12 + r)*s^2 - 8*s^3 + 2*s^4) / (2*Pi*(-13 + r^2 + 24*r*(-1 + s)^2 + 18*s - 6*s^2))) / (n^(3/2) * r^(n - 1/2)), where r = 0.15337200146837895871745857265131731893709232... and s = 1.329726282094188543969222211385207173949290634... are positive real roots of the system of equations r*(4*(-1 + s)^4 + r*s^2) = (2 - 3*s + s^2)^2, 6 + 8*r*(-1 + s)^3 + r^2*s + 9*s^2 = 13*s + 2*s^3. - Vaclav Kotesovec, Jul 22 2024