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 A061804 a(n) = 2*n*(2*n^2 + 1). 5
 0, 6, 36, 114, 264, 510, 876, 1386, 2064, 2934, 4020, 5346, 6936, 8814, 11004, 13530, 16416, 19686, 23364, 27474, 32040, 37086, 42636, 48714, 55344, 62550, 70356, 78786, 87864, 97614, 108060, 119226, 131136, 143814, 157284, 171570, 186696, 202686, 219564 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,2 COMMENTS Sum of n-th row of triangle of even numbers: (2, 4), (6, 8, 10, 12), (14, 16, 18, 20, 22, 24), (26, 28, 30, 32, 34, 36, 38, 40), ..., where n-th row contains 2n terms. Also, integer values of n^3/2 + n. - Arkadiusz Wesolowski, Jul 20 2012 LINKS Harry J. Smith, Table of n, a(n) for n = 0..1000 Index entries for linear recurrences with constant coefficients, signature (4,-6,4,-1). FORMULA a(n) = 6*A005900(n). G.f.: 6*x*(1 + x)^2/(1 - x)^4. - Colin Barker, Apr 20 2012 a(n) = A002061(A002061(n+1)) - A002061(A002061(n)). - Daniel Poveda Parrilla, Jun 10 2017 EXAMPLE a(3) = 114 = 14 + 16 + 18 + 20 + 22 + 24. MAPLE A061804:=n->2*n*(2*n^2 + 1); seq(A061804(n), n=0..50); # Wesley Ivan Hurt, Mar 20 2014 MATHEMATICA Table[2*n*(2*n^2 + 1), {n, 0, 5!}] (* Vladimir Joseph Stephan Orlovsky, Dec 04 2010 *) PROG (PARI) { for (n=0, 1000, write("b061804.txt", n, " ", 2*n*(2*n^2 + 1)) ) } \\ Harry J. Smith, Jul 28 2009 CROSSREFS Cf. A002061, A005900. Sequence in context: A207437 A199243 A172137 * A207421 A207427 A207712 Adjacent sequences:  A061801 A061802 A061803 * A061805 A061806 A061807 KEYWORD nonn,easy AUTHOR Amarnath Murthy, May 28 2001 EXTENSIONS More terms from Larry Reeves (larryr(AT)acm.org) and Alford Arnold, May 29 2001 Better description from Dean Hickerson, Jun 05 2001 STATUS approved

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Last modified May 21 02:48 EDT 2019. Contains 323434 sequences. (Running on oeis4.)