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A096570
Number of compositions of n with first part 2 and no equal adjacent parts; this is column 2 of the array in A096568.
4
0, 1, 1, 0, 2, 4, 5, 10, 18, 29, 53, 95, 161, 283, 500, 869, 1524, 2673, 4665, 8170, 14313, 25032, 43817, 76710, 134228, 234938, 411242, 719720, 1259677, 2204816, 3858882, 6753956, 11821191, 20689807, 36212093, 63380145, 110930372, 194154783
OFFSET
1,5
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