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 A078944 First column of A078939, the fourth power of lower triangular matrix A056857. 28
 1, 4, 20, 116, 756, 5428, 42356, 355636, 3188340, 30333492, 304716148, 3218555700, 35618229364, 411717043252, 4957730174836, 62045057731892, 805323357485684, 10820999695801908, 150271018666120564, 2153476417340487476 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,2 COMMENTS Also, the number of ways of placing n labeled balls into n unlabeled (but 4-colored) boxes. Binomial transform of this sequence is A078945 and a(n+1) = 4*A078945(n). - Paul D. Hanna, Dec 08 2003 First column of PE^4, where PE is given in A011971, second power in A078937, third power in A078938, fourth power in A078939. - Gottfried Helms, Apr 08 2007 The number of ways of putting n labeled balls into a set of bags and then putting the bags into 4 labeled boxes. - Peter Bala, Mar 23 2013 Exponential self-convolution of A001861. - Vladimir Reshetnikov, Oct 06 2016 LINKS Vincenzo Librandi, Table of n, a(n) for n = 0..200 Frank Simon, Algebraic Methods for Computing the Reliability of Networks, Dissertation, Doctor Rerum Naturalium (Dr. rer. nat.), Fakultät Mathematik und Naturwissenschaften der Technischen Universität Dresden, 2012. See Table 5.1. - From N. J. A. Sloane, Jan 04 2013 FORMULA PE=exp(matpascal(5))/exp(1); A = PE^4; a(n)= A[ n,1 ] with exact integer arithmetic: PE=exp(matpascal(5)-matid(6)); A = PE^4; a(n)=A[ n,1]. - Gottfried Helms, Apr 08 2007 E.g.f.: exp(4*(exp(x)-1)). a(n) = exp(-4)*Sum_{k>=0} 4^k*k^n/k!. - Benoit Cloitre, Sep 25 2003 G.f.: 4*(x/(1-x))*A(x/(1-x)) = A(x) - 1; four times the binomial transform equals this sequence shifted one place left. - Paul D. Hanna, Dec 08 2003 a(n) = Sum_{k = 0..n} 4^k*A048993(n, k); A048993: Stirling2 numbers. - Philippe Deléham, May 09 2004 G.f.: (G(0) - 1)/(x-1)/4 where G(k) = 1 - 4/(1-k*x)/(1-x/(x-1/G(k+1))); (recursively defined continued fraction). - Sergei N. Gladkovskii, Jan 16 2013 G.f.: T(0)/(1-4*x), where T(k) = 1 - 4*x^2*(k+1)/(4*x^2*(k+1) - (1-(k+4)*x)*(1-(k+5)*x)/T(k+1); (continued fraction). - Sergei N. Gladkovskii, Oct 28 2013 a(n) ~ n^n * exp(n/LambertW(n/4)-4-n) / (sqrt(1+LambertW(n/4)) * LambertW(n/4)^n). - Vaclav Kotesovec, Mar 12 2014 G.f.: Sum_{j>=0} 4^j*x^j / Product_{k=1..j} (1 - k*x). - Ilya Gutkovskiy, Apr 07 2019 MAPLE A056857 := proc(n, c) combinat[bell](n-1-c)*binomial(n-1, c) ; end: A078937 := proc(n, c) add( A056857(n, k)*A056857(k+1, c), k=0..n) ; end: A078938 := proc(n, c) add( A078937(n, k)*A056857(k+1, c), k=0..n) ; end: A078939 := proc(n, c) add( A078938(n, k)*A056857(k+1, c), k=0..n) ; end: A078944 := proc(n) A078939(n+1, 0) ; end: seq(A078944(n), n=0..25) ; # R. J. Mathar, May 30 2008 MATHEMATICA Table[n!, {n, 0, 20}]CoefficientList[Series[E^(4E^x-4), {x, 0, 20}], x] Table[BellB[n, 4], {n, 0, 20}] (* Vaclav Kotesovec, Mar 12 2014 *) PROG (Sage) expnums(20, 4) # Zerinvary Lajos, Jun 26 2008 CROSSREFS Cf. A000110, A001861, A027710, A056857, A078937, A078938, A078939,  A078944, A078945, A129323, A129324, A129325, A129327, A129328, A129329, A129331, A129332, A129333, A144180, A144223, A144263, A189233, A221159, A221176. Sequence in context: A100328 A082298 A129378 * A158900 A190194 A127088 Adjacent sequences:  A078941 A078942 A078943 * A078945 A078946 A078947 KEYWORD nonn AUTHOR Paul D. Hanna, Dec 18 2002 EXTENSIONS More terms from R. J. Mathar, May 30 2008 Edited by N. J. A. Sloane, Jul 02 2008 at the suggestion of R. J. Mathar STATUS approved

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Last modified November 23 21:51 EST 2020. Contains 338603 sequences. (Running on oeis4.)