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A096571
Number of compositions of n with first part 3 and no equal adjacent parts; this is column 3 of the array in A096568.
4
0, 0, 1, 1, 1, 2, 3, 6, 12, 20, 33, 59, 104, 181, 319, 557, 971, 1705, 2985, 5218, 9138, 15993, 27984, 48992, 85749, 150061, 262656, 459721, 804597, 1408263, 2464815, 4313962, 7550509, 13215258, 23129801, 40482775, 70854694, 124012664
OFFSET
1,6
FORMULA
Define s(0)=1, T(1, 1)=1 and T(i, j)=0 for j>i. For n>=2 and 1<=k<=n, define s(n)=T(n, 1)+T(n, 2)+...+T(n, n) and T(n, k)=s(n-k)-T(n-k, k). (This is array A096568.)
CROSSREFS
KEYWORD
nonn
AUTHOR
Clark Kimberling, Jun 27 2004
STATUS
approved