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A052790
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A simple grammar.
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0
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0, 0, 0, 0, 0, 0, 720, 10080, 114240, 1270080, 14621040, 177629760, 2292618240, 31485168000, 459767275968, 7126635035520, 117007217832960, 2030137891891200, 37138576448883456, 714734162773420032
(list; graph; refs; listen; history; internal format)
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OFFSET
| 0,7
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LINKS
| INRIA Algorithms Project, Encyclopedia of Combinatorial Structures 747
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FORMULA
| E.g.f.: x^2*ln(-1/(-1+x))^4
Recurrence: {a(1)=0, a(2)=0, a(4)=0, a(3)=0, a(5)=0, a(6)=720, (32*n-464*n^2-21*n^6-22*n^5+48*n^3+n^8+2*n^7+384+160*n^4)*a(n)+(105*n^4-360-14*n^6-121*n^2-4*n^7+642*n-296*n^3+48*n^5)*a(n+1)+(-84*n+24*n^5+179*n^2+6*n^6-35*n^4-90*n^3)*a(n+2)+(14*n^2+12*n^3-8*n-14*n^4-4*n^5)*a(n+3)+(-n^2+n^4-2*n+2*n^3)*a(n+4)}
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MAPLE
| spec := [S, {B=Cycle(Z), S=Prod(Z, Z, B, B, B, B)}, labeled]: seq(combstruct[count](spec, size=n), n=0..20);
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CROSSREFS
| Sequence in context: A052786 A187192 A052792 * A052521 A052785 A052783
Adjacent sequences: A052787 A052788 A052789 * A052791 A052792 A052793
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KEYWORD
| easy,nonn
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AUTHOR
| encyclopedia(AT)pommard.inria.fr, Jan 25 2000
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