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 A152750 Eight times hexagonal numbers: 8*n*(2*n-1). 5
 0, 8, 48, 120, 224, 360, 528, 728, 960, 1224, 1520, 1848, 2208, 2600, 3024, 3480, 3968, 4488, 5040, 5624, 6240, 6888, 7568, 8280, 9024, 9800, 10608, 11448, 12320, 13224, 14160, 15128, 16128, 17160, 18224, 19320, 20448, 21608, 22800, 24024, 25280, 26568 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,2 COMMENTS Equals Engel expansion of cosh(1/2), except first member (see A067239). Also sequence found by reading the line from 0, in the direction 0, 8, ..., in the square spiral whose vertices are the generalized decagonal numbers A074377. - Omar E. Pol, Sep 18 2011 a(n) = the sum of the edges of a rectangular prism having edges 2*(n-1)*n, n^2-(n-1)^2 and n^2 + (n-1)^2. - J. M. Bergot, Apr 24 2014 LINKS Ivan Panchenko, Table of n, a(n) for n = 0..1000 Index entries for linear recurrences with constant coefficients, signature (3,-3,1). FORMULA a(n) = 16n^2 - 8n = A000384(n)*8 = A002939(n)*4 = A085250(n)*2. a(n) = A067239(n), for n>0. a(n) = a(n-1)+32*n-24 (with a(0)=0). - Vincenzo Librandi, Nov 26 2010 From Colin Barker, Sep 25 2016: (Start) a(n) = 3*a(n-1)-3*a(n-2)+a(n-3) for n>2. G.f.: 8*x*(1+3*x) / (1-x)^3. (End) Sum_{n>=1} 1/a(n) = log(2)/4. - Vaclav Kotesovec, Sep 25 2016 MAPLE A152750:=n->8*n*(2*n-1); seq(A152750(n), n=0..50); # Wesley Ivan Hurt, Jun 09 2014 MATHEMATICA Table[8*n*(2*n - 1), {n, 0, 50}] (* Wesley Ivan Hurt, Jun 09 2014 *) PROG (MAGMA) [ 8*n*(2*n-1) : n in [0..50] ]; // Wesley Ivan Hurt, Jun 09 2014 (PARI) concat(0, Vec(8*x*(1+3*x)/(1-x)^3 + O(x^50))) \\ Colin Barker, Sep 25 2016 CROSSREFS Cf. A000384, A002939, A067239, A085250. Sequence in context: A139279 A250257 A067239 * A121355 A227499 A168012 Adjacent sequences:  A152747 A152748 A152749 * A152751 A152752 A152753 KEYWORD easy,nonn AUTHOR Omar E. Pol, Dec 12 2008 STATUS approved

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Last modified March 23 23:06 EDT 2019. Contains 321443 sequences. (Running on oeis4.)