A052783 A simple grammar.

0, 0, 0, 0, 0, 0, 720, 12600, 168000, 2116800, 26938800, 355509000, 4920379200, 71753338800, 1104107484480, 17923866760800, 306665482905600, 5521899225024000, 104470579944195840, 2073203785324575360

Offset

0,7

Links

Table of n, a(n) for n=0..19.

INRIA Algorithms Project, Encyclopedia of Combinatorial Structures 740

Formula

E.g.f.: x*log(-1/(-1+x))^5.

Recurrence: {a(1)=0, a(2)=0, a(4)=0, a(3)=0, a(5)=0, a(6)=720, (500*n^3 + 55*n^2 - 300*n^4 - n^10 + 120 - 224*n^5 - 20*n^8 + 146*n^6 - 10*n^9 + 60*n^7 - 326*n)*a(n) + (225*n^7 - n^4 - 299*n^5 + 120*n + 60*n^8 + 5*n^9 + 195*n^6 - 446*n^2 + 501*n^3)*a(n + 1) + ( - 535*n^3 - 895*n^4 - 10*n^8 - 130*n^7 - 300*n^2 - 1135*n^5 - 595*n^6)*a(n + 2) + (130*n^6 + 10*n^7 + 200*n + 1425*n^3 + 1330*n^4 + 615*n^5 + 790*n^2)*a(n + 3) + ( - 150*n - 455*n^2 - 60*n^5 - 5*n^6 - 510*n^3 - 260*n^4)*a(n + 4) + (n^5 + 10*n^4 + 35*n^3 + 50*n^2 + 24*n)*a(n + 5)}.

Maple

spec := [S, {B=Cycle(Z), S=Prod(Z, B, B, B, B, B)}, labeled]: seq(combstruct[count](spec, size=n), n=0..20);

Crossrefs

Sequence in context: A052521 A213876 A052785 * A112002 A004033 A056271

Adjacent sequences: A052780 A052781 A052782 * A052784 A052785 A052786

Keyword

easy,nonn

Author

encyclopedia(AT)pommard.inria.fr, Jan 25 2000

Status

approved