cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

Showing 1-2 of 2 results.

A163832 a(n) = n*(2*n^2 + 5*n + 1).

Original entry on oeis.org

0, 8, 38, 102, 212, 380, 618, 938, 1352, 1872, 2510, 3278, 4188, 5252, 6482, 7890, 9488, 11288, 13302, 15542, 18020, 20748, 23738, 27002, 30552, 34400, 38558, 43038, 47852, 53012, 58530, 64418, 70688, 77352, 84422, 91910, 99828, 108188, 117002
Offset: 0

Views

Author

Vincenzo Librandi, Aug 05 2009

Keywords

Comments

Row sums of triangle A155156.

Crossrefs

Cf. A155156.

Programs

  • Mathematica
    Table[n(2n^2+5n+1),{n,0,40}] (* or *) LinearRecurrence[{4,-6,4,-1},{0,8,38,102},40] (* Harvey P. Dale, Feb 02 2012 *)
  • PARI
    for(n=0, 40, print1(n*(2*n^2+5*n+1)", ")); \\ Vincenzo Librandi, Feb 22 2012

Formula

G.f.: -2*x*(1+x)*(x-4)/(x-1)^4.
a(n) = 4*a(n-1) -6*a(n-2) +4*a(n-3) -a(n-4).
a(n) = A163683(n) + n = A163815(n) - 2*n = 2*A162254(n).
a(n) = -n*A168244(n+2). - Bruno Berselli, Feb 02 2012
E.g.f.: x*(8 + 11*x + 2*x^2)*exp(x). - G. C. Greubel, Aug 05 2017

Extensions

Edited by R. J. Mathar, Aug 05 2009

A163676 Triangle T(n,m) = 4mn + 2m + 2n - 1 read by rows.

Original entry on oeis.org

7, 13, 23, 19, 33, 47, 25, 43, 61, 79, 31, 53, 75, 97, 119, 37, 63, 89, 115, 141, 167, 43, 73, 103, 133, 163, 193, 223, 49, 83, 117, 151, 185, 219, 253, 287, 55, 93, 131, 169, 207, 245, 283, 321, 359, 61, 103, 145, 187, 229, 271, 313, 355, 397, 439, 67, 113, 159
Offset: 1

Views

Author

Vincenzo Librandi, Aug 03 2009

Keywords

Comments

2 + T(n,m) = (2*n+1)*(2*m+1) are composite numbers. - clarified by R. J. Mathar, Oct 16 2009
First column: A016921, second column: A017305, third column: A126980. - Vincenzo Librandi, Nov 21 2012

Examples

			Triangle begins:
   7;
  13,  23;
  19,  33,  47;
  25,  43,  61,  79;
  31,  53,  75,  97, 119;
  37,  63,  89, 115, 141, 167;
  43,  73, 103, 133, 163, 193, 223;
  49,  83, 117, 151, 185, 219, 253, 287;
  55,  93, 131, 169, 207, 245, 283, 321, 359;
  61, 103, 145, 187, 229, 271, 313, 355, 397, 439;
		

Crossrefs

Programs

  • Magma
    [4*n*k + 2*n + 2*k - 1: k in [1..n], n in [1..11]]; // Vincenzo Librandi, Nov 21 2012
    
  • Mathematica
    t[n_,k_]:=4 n*k + 2n + 2k - 1; Table[t[n, k], {n, 15}, {k, n}]//Flatten (* Vincenzo Librandi, Nov 21 2012 *)
  • PARI
    for(n=1,10, for(k=1,n, print1(4*n*k + 2*n + 2*k - 1, ", "))) \\ G. C. Greubel, Aug 02 2017

Formula

T(n,m) = A155151(n,m) - 3 = A155156(n,m) - 1. - R. J. Mathar, Oct 16 2009
Showing 1-2 of 2 results.