A011810 M-sequences from multicomplexes on 4 variables with all monomials of degree 2 but none of degree larger than n.

0, 0, 1, 21, 330, 4931, 76064, 1257345, 22707559, 452800399, 10023029299, 246756095614, 6752175162108, 204875755372586, 6868905893537535, 253432530143048034, 10246233216680784186, 452038162651568624259

Offset

0,4

References

S. Linusson, The number of M-sequences and f-vectors, Combinatorica, 19 (1999), 255-266.

Links

Table of n, a(n) for n=0..17.

Formula

a(n) = Sum_{k=2..n} L(4, n, k) where L(p, n, k) = Sum_{i=k..n} L(p-1, n, i) * L(p, i-1, k-1) with boundary conditions L(p, n, n) = L(p, n, -1) = 1 (p >= 0, n >= -1), L(0, n, k) = 0 (0 <= k < n) [from Linusson].

Crossrefs

Sequence in context: A340097 A237856 A016260 * A091947 A016195 A322540

Adjacent sequences: A011807 A011808 A011809 * A011811 A011812 A011813

Keyword

nonn

Author

Svante Linusson (linusson(AT)math.kth.se)

Extensions

Offset corrected by Sean A. Irvine, Jun 28 2018

Status

approved