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A124376 Number triangle with column k generated by x^k*(1+2kx+C(k,2)*x^2)/(1-x)^(k+1). 0
1, 1, 1, 1, 4, 1, 1, 7, 7, 1, 1, 10, 19, 10, 1, 1, 13, 37, 37, 13, 1, 1, 16, 61, 92, 61, 16, 1, 1, 19, 91, 185, 185, 91, 19, 1, 1, 22, 127, 326, 440, 326, 127, 22, 1, 1, 25, 169, 525, 896, 896, 525, 169, 25, 1, 1, 28, 217, 792 (list; table; graph; refs; listen; history; text; internal format)
OFFSET
0,5
COMMENTS
Columns include A016777,A003215,A096000. T(n,k)=T(n-k,k).
LINKS
FORMULA
Number triangle T(n,k)=sum{j=0..n, C(k,k-j)*C(n-j,k)*C(2,j)}*[k<=n]
EXAMPLE
Triangle begins
1,
1, 1,
1, 4, 1,
1, 7, 7, 1,
1, 10, 19, 10, 1,
1, 13, 37, 37, 13, 1,
1, 16, 61, 92, 61, 16, 1,
1, 19, 91, 185, 185, 91, 19, 1
CROSSREFS
Sequence in context: A157172 A131060 A350512 * A047671 A081577 A146986
KEYWORD
easy,nonn,tabl
AUTHOR
Paul Barry, Oct 28 2006
STATUS
approved

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Last modified March 28 11:59 EDT 2024. Contains 371254 sequences. (Running on oeis4.)