close
login
A007190
Multiplicative encoding of Stirling numbers of 2nd kind.
(Formerly M1724)
2
2, 6, 270, 478406250, 26574922713477178215980529785156250
OFFSET
1,1
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.
John Riordan, An Introduction to Combinatorial Analysis, Wiley, 1958, p. 48.
N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).
LINKS
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].
N. J. A. Sloane, An on-line version of the Encyclopedia of Integer Sequences, Electronic J. Combinatorics, Vol. 1, No. 1 (1994), Article F1.
FORMULA
a(n) = Product_{k=1..n} prime(n)^Stirling2(n, k). - Sean A. Irvine, Nov 15 2017
MATHEMATICA
a[n_] := Product[Prime[k]^Abs[StirlingS2[n, k]], {k, 1, n}]; Array[a, 5] (* Amiram Eldar, Aug 19 2025 *)
PROG
(PARI) a(n) = prod(k=1, n, prime(n)^stirling(n, k, 2)); \\ Michel Marcus, Apr 20 2022
CROSSREFS
KEYWORD
nonn
STATUS
approved