login

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).

A059364
Triangle T(n,k)=Sum_{i=0..n} |stirling1(n,n-i)|*binomial(i,k), k=0..n-1.
2
1, 2, 1, 6, 7, 2, 24, 46, 29, 6, 120, 326, 329, 146, 24, 720, 2556, 3604, 2521, 874, 120, 5040, 22212, 40564, 39271, 21244, 6084, 720, 40320, 212976, 479996, 598116, 444849, 197380, 48348, 5040, 362880, 2239344, 6023772, 9223012, 8788569
OFFSET
1,2
COMMENTS
Sum_{k=0..n-1} T(n,k)=(2*n-1)!!.
Alternating row sums = 1. - Gerald McGarvey, Aug 06 2006
Essentially triangle given by [1,1,2,2,3,3,4,4,5,5,6,6,...] DELTA [0,1,1,2,2,3,3,4,4,5,5,...] = [1;1,0;2,1,0;6,7,2,0;24,46,29,6,0;...] where DELTA is the operator defined in A084938. - Philippe Deléham, Nov 20 2006
LINKS
Grzegorz Rzadkowski and M. Urlinska, A Generalization of the Eulerian Numbers, arXiv preprint arXiv:1612.06635 [math.CO], 2016-2017.
FORMULA
For n>1, T(n,k) = (n-1)*T(n-1,k-1) + n*T(n-1,k) (assuming any T(i,j) outside the triangle = 0). - Gerald McGarvey, Aug 06 2006
EXAMPLE
[1],
[2, 1],
[6, 7, 2],
[24, 46, 29, 6],
[120, 326, 329, 146, 24],
[720, 2556, 3604, 2521, 874, 120], ...
2+1=3!!, 6+7+2=5!!, 24+46+29+6=7!!, 120+326+329+146+24=9!!.
MATHEMATICA
Table[Sum[Abs[StirlingS1[n, n - j]]*Binomial[j, k], {j, 0, n}], {n, 1, 10}, {k, 0, n - 1}] // Flatten (* G. C. Greubel, Jan 08 2017 *)
PROG
(PARI) T(n, k)=if(n<1, 0, n!*polcoeff(polcoeff((1-x-x*y+x*O(x^n))^(-1/(1+y)), n), k))
(Sage)
def A059364(n, k): return add(stirling_number1(n, n-i)*binomial(i, k) for i in (0..n))
for n in (1..5): [A059364(n, k) for k in (0..n-1)] # Peter Luschny, May 12 2013
CROSSREFS
Sequence in context: A084312 A066752 A192329 * A258870 A217922 A196554
KEYWORD
easy,nonn,tabl
AUTHOR
Vladeta Jovovic, Jan 28 2001
STATUS
approved