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A077227 Triangle of compositions of n into exactly k parts each no more than k. 2
1, 0, 1, 0, 2, 1, 0, 1, 3, 1, 0, 0, 6, 4, 1, 0, 0, 7, 10, 5, 1, 0, 0, 6, 20, 15, 6, 1, 0, 0, 3, 31, 35, 21, 7, 1, 0, 0, 1, 40, 70, 56, 28, 8, 1, 0, 0, 0, 44, 121, 126, 84, 36, 9, 1, 0, 0, 0, 40, 185, 252, 210, 120, 45, 10, 1, 0, 0, 0, 31, 255, 456, 462, 330, 165, 55, 11, 1, 0, 0, 0, 20 (list; table; graph; refs; listen; history; internal format)
OFFSET

1,5

LINKS

Index entries for sequences related to compositions

FORMULA

T(n, k) =A077228(n, k)-A077228(n-1, k). If n>=k^2, T(n, k)=0. If k<=n<2k, T(n, k)=C(n-1, k-1).

EXAMPLE

Rows start: 1; 0,1; 0,2,1; 0,1,3,1; 0,0,6,4,1; 0,0,7,10,5,1; etc. Columns start: 1,0,0,0,...; 1,2,1,0,0,0,...; 1,3,6,7,6,3,1,0,0,0,...; 1,4,10,20,31,40,44,40,31,20,10,4,1,0,0,0,...; etc. T(6,3)=7 since 6 can be written as 1+2+3, 1+3+2, 2+1+3, 2+2+2, 2+3+1, 3+1+2, or 3+2+1.

CROSSREFS

Column sums are A000312. Row sums are A077229. Central diagonal is A000984 offset. Right hand side is right hand side of A007318. Cf. A077228.

Sequence in context: A131185 A052249 A030528 * A089263 A156135 A047265

Adjacent sequences:  A077224 A077225 A077226 * A077228 A077229 A077230

KEYWORD

nonn,tabl

AUTHOR

Henry Bottomley (se16(AT)btinternet.com), Oct 29 2002

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Last modified February 14 07:16 EST 2012. Contains 205589 sequences.