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A048993 Triangle of Stirling numbers of 2nd kind, S(n,k), n >= 0, 0<=k<=n. 91
1, 0, 1, 0, 1, 1, 0, 1, 3, 1, 0, 1, 7, 6, 1, 0, 1, 15, 25, 10, 1, 0, 1, 31, 90, 65, 15, 1, 0, 1, 63, 301, 350, 140, 21, 1, 0, 1, 127, 966, 1701, 1050, 266, 28, 1, 0, 1, 255, 3025, 7770, 6951, 2646, 462, 36, 1, 0, 1, 511, 9330, 34105, 42525, 22827, 5880, 750, 45, 1 (list; table; graph; refs; listen; history; text; internal format)
OFFSET

0,9

COMMENTS

Also known as Stirling set numbers.

S(n,k) enumerates partitions of an n-set into k non-empty subsets.

The o.g.f. for the sequence of diagonal k (k=0 for the main diagonal) is G(k,x)= ((x^k)/(1-x)^(2*k+1))*sum(A008517(k,m+1)*x^m,m=0..k-1). A008517 is the second-order Eulerian triangle. - Wolfdieter Lang, Oct 14 2005.

From Philippe Deléham, Nov 14 2007: (Start)

Sum_{k, 0<=k<=n}S(n,k)*x^k = B_n(x), where B_n(x) = Bell polynomials. The first few Bell polynomials are:

B_0(x) = 1;

B_1(x) = 0 + x;

B_2(x) = 0 + x + x^2;

B_3(x) = 0 + x + 3x^2 + x^3;

B_4(x) = 0 + x + 7x^2 + 6x^3 + x^4;

B_5(x) = 0 + x + 15x^2 + 25x^3 + 10x^4 + x^5;

B_6(x) = 0 + x + 31x^2 + 90x^3 + 65x^4 + 15x^5 + x^6;

(End)

REFERENCES

M. Abramowitz and I. A. Stegun, eds., Handbook of Mathematical Functions, National Bureau of Standards Applied Math. Series 55, 1964 (and various reprintings), p. 835.

P. Barry, Generalized Stirling Numbers, Exponential Riordan Arrays, and Toda Chain Equations, Journal of Integer Sequences, 17 (2014), #14.2.3.

P. Barry, Constructing Exponential Riordan Arrays from Their A and Z Sequences, Journal of Integer Sequences, 17 (2014), #14.2.6.

L. Comtet, Advanced Combinatorics, Reidel, 1974, p. 310.

J. H. Conway and R. K. Guy, The Book of Numbers, Springer, p. 92.

F. N. David, M. G. Kendall and D. E. Barton, Symmetric Function and Allied Tables, Cambridge, 1966, p. 223.

R. L. Graham, D. E. Knuth and O. Patashnik, Concrete Mathematics. Addison-Wesley, Reading, MA, 1990, p. 244.

W. S. Gray and M. Thitsa, System Interconnections and Combinatorial Integer Sequences, in: System Theory (SSST), 2013 45th Southeastern Symposium on, Date of Conference: 11-11 March 2013, Digital Object Identifier: 10.1109/SSST.2013.6524939.

J. Riordan, An Introduction to Combinatorial Analysis, p. 48.

X.-T. Su, D.-Y. Yang, W.-W. Zhang, A note on the generalized factorial, Australasian Journal of Combinatorics, Volume 56 (2013), Pages 133-137.

LINKS

David W. Wilson, Table of n, a(n) for n = 0..10010

M. Abramowitz and I. A. Stegun, eds., Handbook of Mathematical Functions, National Bureau of Standards, Applied Math. Series 55, Tenth Printing, 1972 [alternative scanned copy].

R. M. Dickau, Stirling numbers of the second kind

G. Duchamp, K. A. Penson, A. I. Solomon, A. Horzela and P. Blasiak, One-parameter groups and combinatorial physics.

FORMULA

S(n, k) = k*S(n-1, k)+S(n-1, k-1), n>0; S(0, k) = 0, k>0; S(0, 0)=1.

Equals [0, 1, 0, 2, 0, 3, 0, 4, 0, 5, ..] DELTA [1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, ...] where DELTA is Deléham's operator defined in A084938.

Sum_{k = 0..n} x^k*S(n, k) = A213170(n), A000587(n), A000007(n), A000110(n), A001861(n), A027710(n), A078944(n), A144180(n), A144223(n), A144263(n) respectively for x = -2, -1, 0, 1, 2, 3, 4, 5, 6, 7 . - Philippe Deléham, May 09 2004, Feb 16 2013

S(n, k)=sum{i=0..k, (-1)^(k+i)binomial(k, i)i^n/k!} - Paul Barry, Aug 05 2004

Sum(k*S(n,k), k=0..n)=B(n+1)-B(n), where B(q) are the Bell numbers (A000110). - Emeric Deutsch, Nov 01 2006

Equals the inverse binomial transform of A008277 - Gary W. Adamson, Jan 29 2008

G.f.: 1/(1-xy/(1-x/(1-xy/(1-2x/(1-xy/1-3x/(1-xy/(1-4x/(1-xy/(1-5x/(1-... (continued fraction equivalent to Deleham DELTA construction). [Paul Barry, Dec 06 2009]

G.f.: 1/Q(0), where Q(k) = 1 -(y+k)*x - (k+1)*y*x^2/Q(k+1) ; (continued fraction). - Sergei N. Gladkovskii, Nov 09 2013

EXAMPLE

Triangle begins:

1

0 1

0 1 1

0 1 3 1

0 1 7 6 1

0 1 15 25 10 1

0 1 31 90 65 15 1

...

MAPLE

with(combinat): for n from 0 to 10 do seq(stirling2(n, k), k=0..n) od; # yields sequence in triangular form - Emeric Deutsch, Nov 01 2006

MATHEMATICA

t[n_, k_] := StirlingS2[n, k]; Table[t[n, k], {n, 0, 10}, {k, 0, n}] // Flatten (* Robert G. Wilson v *)

PROG

(PARI) for(n=0, 22, for(k=0, n, print1(stirling(n, k, 2), ", ")); print()); \\ Joerg Arndt, Apr 21 2013

(Maxima) create_list(stirling2(n, k), n, 0, 12, k, 0, n); /* Emanuele Munarini, Mar 11 2011 */

(Haskell)

a048993 n k = a048993_tabl !! n !! k

a048993_row n = a048993_tabl !! n

a048993_tabl = iterate (\row ->

   [0] ++ (zipWith (+) row $ zipWith (*) [1..] $ tail row) ++ [1]) [1]

-- Reinhard Zumkeller, Mar 26 2012

CROSSREFS

See especially A008277 which is the main entry for this triangle.

Cf. A008275, A039810-A039813, A048994.

A000110(n) = sum(S(n, k)) k=0..n, n >= 0. Cf. A085693.

Cf. A084938, A106800 (mirror image), A213061.

Sequence in context: A144644 A151509 A151511 * A193357 A112413 A122960

Adjacent sequences:  A048990 A048991 A048992 * A048994 A048995 A048996

KEYWORD

nonn,tabl,nice

AUTHOR

N. J. A. Sloane.

STATUS

approved

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Last modified April 18 19:33 EDT 2014. Contains 240733 sequences.