The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A001247 Squares of Bell numbers. 16
 1, 1, 4, 25, 225, 2704, 41209, 769129, 17139600, 447195609, 13450200625, 460457244900, 17754399678409, 764214897046969, 36442551140059684, 1912574337188517025, 109833379421325769609, 6866586647633870998416, 465228769500062060333281 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,3 REFERENCES C. M. Bender, D. C. Brody and B. K. Meister, Quantum Field Theory of Partitions, J. Math. Phys., 40,7 (1999), 3239-45. LINKS T. D. Noe, Table of n, a(n) for n = 0..100 C. M. Bender et al., Combinatorics and Field theory, arXiv:quant-ph/0604164, 2006. FORMULA E.g.f.: exp(exp(x*(d_z) - 1))*(exp(exp(z) - 1)) |_{z = 0}, with the derivative operator d_z := d/dz. From equations (16) and (17) of Bender et al. (1999). E.g.f.: exp(-2)*Sum(exp(exp(n*x))/n!, n = 0..infinity). - Vladeta Jovovic, Jan 31 2008 MAPLE with(combinat): seq(bell(n)^2), n=0..17); # Zerinvary Lajos, Sep 21 2007 MATHEMATICA Table[BellB[n, 1]^2, {n, 0, 17}] (* Zerinvary Lajos, Jul 16 2009 *) PROG (Sage) [(bell_number(n))^2 for n in range(0, 18)] # Zerinvary Lajos, May 15 2009 (MAGMA) [Bell(n)^2: n in [0..20]]; // Vincenzo Librandi, Jul 16 2013 CROSSREFS Cf. A000110. Sequence in context: A246951 A302587 A302608 * A031152 A010845 A087660 Adjacent sequences:  A001244 A001245 A001246 * A001248 A001249 A001250 KEYWORD nonn,easy AUTHOR STATUS approved

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

Last modified May 30 18:38 EDT 2020. Contains 334728 sequences. (Running on oeis4.)