login
The OEIS is supported by the many generous donors to the OEIS Foundation.

 

Logo
Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A000497 S2(j,2j+2) where S2(n,k) is a 2-associated Stirling number of the second kind.
(Formerly M5186 N2254)
2

%I M5186 N2254 #36 Jun 09 2018 09:20:27

%S 1,25,490,9450,190575,4099095,94594500,2343240900,62199262125,

%T 1764494857125,53338158823950,1712934942468750,58274046742786875,

%U 2094379201311271875,79318164037837725000,3157886388887074845000

%N S2(j,2j+2) where S2(n,k) is a 2-associated Stirling number of the second kind.

%D L. Comtet, Advanced Combinatorics, Reidel, 1974, p. 256.

%D F. N. David and D. E. Barton, Combinatorial Chance. Hafner, NY, 1962, p. 296.

%D N. J. A. Sloane, A Handbook of Integer Sequences, Academic Press, 1973 (includes this sequence).

%D N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).

%H Vincenzo Librandi, <a href="/A000497/b000497.txt">Table of n, a(n) for n = 1..100</a>

%H H. W. Gould, Harris Kwong, Jocelyn Quaintance, <a href="https://cs.uwaterloo.ca/journals/JIS/VOL18/Kwong/kwong9.html">On Certain Sums of Stirling Numbers with Binomial Coefficients</a>, J. Integer Sequences, 18 (2015), #15.9.6.

%H M. Ward, <a href="http://www.jstor.org/stable/2370916">The representations of Stirling's numbers and Stirling's polynomials as sums of factorials</a>, Amer. J. Math., 56 (1934), p. 87-95.

%F G.f.: x*(4*x+1)*hypergeom([3, 7/2],[],2*x)+28*x^3*hypergeom([4, 9/2],[],2*x). - _Mark van Hoeij_, Apr 07 2013

%F a(n) = n*(n+1)*(2*n+1)*2^n*GAMMA(n+3/2)/(9*sqrt(Pi)). - _Vaclav Kotesovec_, Aug 07 2013

%F (2*n-1)*(n-1)*a(n) -(n+1)*(1+2*n)^2*a(n-1)=0. - _R. J. Mathar_, Jun 09 2018

%p gf := (u,t)->exp(u*(exp(t)-1-t)); S2a := j->simplify(subs(u=0,t=0,diff(gf(u,t),u$j,t$(2*j+2)))/j!); for i from 1 to 20 do S2a(i); od;

%p # Barbara Haas Margolius (margolius(AT)math.csuohio.edu), Dec 12 2000

%t t[n_, k_] := Sum[ (-1)^i*Binomial[n, i]*Sum[ (-1)^j*(k-i-j)^(n-i)/(j!*(k-i-j)!), {j, 0, k-i}], {i, 0, k}]; Table[ t[2n+2, n], {n, 1, 16} ](* _Jean-François Alcover_, Feb 24 2012 *)

%t Table[n*(n+1)*(2*n+1)*2^n*Gamma[n+3/2]/(9*Sqrt[Pi]),{n,1,20}] (* _Vaclav Kotesovec_, Aug 07 2013 *)

%Y Cf. A008299, A000504.

%K nonn,nice,easy

%O 1,2

%A _N. J. A. Sloane_

%E More terms from Barbara Haas Margolius (margolius(AT)math.csuohio.edu), Dec 12 2000

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recents
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified March 28 10:55 EDT 2024. Contains 371241 sequences. (Running on oeis4.)