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.

Previous Showing 11-14 of 14 results.

A022271 a(n) = n*(13*n + 1)/2.

Original entry on oeis.org

0, 7, 27, 60, 106, 165, 237, 322, 420, 531, 655, 792, 942, 1105, 1281, 1470, 1672, 1887, 2115, 2356, 2610, 2877, 3157, 3450, 3756, 4075, 4407, 4752, 5110, 5481, 5865, 6262, 6672, 7095, 7531, 7980, 8442, 8917, 9405, 9906, 10420, 10947, 11487, 12040
Offset: 0

Views

Author

Keywords

Crossrefs

Cf. similar sequences listed in A022289.

Programs

Formula

a(n) = A110449(n, 6) for n>5.
a(n) = 13*n + a(n-1) - 6 with n>0, a(0)=0. - Vincenzo Librandi, Aug 04 2010
G.f.: x*(7+6*x)/(1-x)^3. - Vincenzo Librandi, Mar 31 2015
a(n) = 3*a(n-1) - 3*a(n-2) + a(n-3) for n>2 - Vincenzo Librandi, Mar 31 2015
a(n) = A022270(-n). - Bruno Berselli, Mar 31 2015
a(n) = A000217(7*n) - A000217(6*n). - Bruno Berselli, Oct 13 2016
E.g.f.: (x/2)*(13*x + 14)*exp(x). - G. C. Greubel, Aug 23 2017

Extensions

More terms from Vincenzo Librandi, Mar 31 2015

A085786 a(n) = n*(2*n^2 + n + 1)/2.

Original entry on oeis.org

2, 11, 33, 74, 140, 237, 371, 548, 774, 1055, 1397, 1806, 2288, 2849, 3495, 4232, 5066, 6003, 7049, 8210, 9492, 10901, 12443, 14124, 15950, 17927, 20061, 22358, 24824, 27465, 30287, 33296, 36498, 39899, 43505, 47322, 51356, 55613, 60099, 64820
Offset: 1

Views

Author

Jon Perry, Jul 23 2003

Keywords

Crossrefs

Cf. A000217 [t(n)], A000096 [t(n)+n], A005449 [t(n)+n^2].
a(n) = A110449(n, n).

Programs

  • Magma
    [n*(2*n^2 + n + 1)/2: n in [1..40]]; // Vincenzo Librandi, Aug 14 2017
  • Mathematica
    CoefficientList[Series[(x + 1) (x + 2) / (x - 1)^4, {x, 0, 40}], x] (* or *) LinearRecurrence[{4, -6, 4, -1}, {2, 11, 33, 74}, 40] (* Vincenzo Librandi, Aug 14 2017 *)
  • PARI
    t(n)=n*(n+1)/2;
    vector(40, i, t(i)+i^3)
    

Formula

a(n) = A000217(n) + n^3.
From Colin Barker, Jan 20 2014: (Start)
a(n) = 4*a(n-1) - 6*a(n-2) + 4*a(n-3) - a(n-4).
G.f.: x*(x+1)*(x+2) / (x-1)^4. (End)
E.g.f.: (x/2)*(4 + 7*x + 2*x^2)*exp(x). - G. C. Greubel, Aug 24 2017

Extensions

Name changed by Wesley Ivan Hurt, Apr 30 2022

A022273 a(n) = n*(15*n + 1)/2.

Original entry on oeis.org

0, 8, 31, 69, 122, 190, 273, 371, 484, 612, 755, 913, 1086, 1274, 1477, 1695, 1928, 2176, 2439, 2717, 3010, 3318, 3641, 3979, 4332, 4700, 5083, 5481, 5894, 6322, 6765, 7223, 7696, 8184, 8687, 9205, 9738, 10286, 10849, 11427, 12020, 12628, 13251, 13889
Offset: 0

Views

Author

Keywords

Crossrefs

Cf. similar sequences listed in A022289.

Programs

Formula

a(n) = A110449(n, 7) for n>6.
a(n) = 15*n + a(n-1) - 7 for n>0, a(0)=0. - Vincenzo Librandi, Aug 04 2010
G.f.: x*(8+7*x)/(1-x)^3. - Vincenzo Librandi, Mar 31 2015
a(n) = 3*a(n-1) - 3*a(n-2) - a(n-3) for n>2. - Vincenzo Librandi, Mar 31 2015
a(n) = A022272(-n). - Bruno Berselli, Mar 31 2015
a(n) + a(-n) = A064761(n). - Bruno Berselli, Mar 31 2015
a(n) = A000217(8*n) - A000217(7*n). - Bruno Berselli, Oct 13 2016
E.g.f.: (x/2)*(15*x + 16)*exp(x). - G. C. Greubel, Aug 23 2017

Extensions

More terms from Vincenzo Librandi, Mar 31 2015

A110451 a(n) = n*(4*n^2 + 2*n + 1).

Original entry on oeis.org

0, 7, 42, 129, 292, 555, 942, 1477, 2184, 3087, 4210, 5577, 7212, 9139, 11382, 13965, 16912, 20247, 23994, 28177, 32820, 37947, 43582, 49749, 56472, 63775, 71682, 80217, 89404, 99267, 109830, 121117, 133152, 145959, 159562, 173985, 189252
Offset: 0

Views

Author

Reinhard Zumkeller, Jul 21 2005

Keywords

Comments

a(n) = A110449(2*n,n), central terms in triangle A110449.
2*a(n) is the sum of the consecutive integers from A000384(n)+1 to A000384(n+1)-1. - Bruno Berselli, Jun 27 2018

Crossrefs

Programs

  • GAP
    List([0..40],n->n*(4*n^2+2*n+1)); # Muniru A Asiru, Jun 27 2018
  • Magma
    [n*(4*n^2+2*n+1): n in [0..40]]; // Vincenzo Librandi, Dec 26 2010
    
  • Maple
    seq(n*(4*n^2+2*n+1),n=0..40); # Muniru A Asiru, Jun 27 2018
  • Mathematica
    Table[n*(4*n^2 + 2*n + 1), {n, 0, 50}] (* or *) LinearRecurrence[{4,-6,4,-1}, {0,7,42,129}, 50] (* G. C. Greubel, Aug 24 2017 *)
  • PARI
    x='x+O('x^50); Vec((7*x + 14*x^2 + 3*x^3)/(1 - x)^4) \\ G. C. Greubel, Aug 24 2017
    

Formula

From G. C. Greubel, Aug 24 2017: (Start)
a(n) = 4*a(n-1) - 6*a(n-1) + 4*a(n-2) - a(n-4).
G.f.: (7*x + 14*x^2 + 3*x^3)/(1 - x)^4.
E.g.f.: x*(7 + 14*x + 4*x^2)*exp(x). (End)
Previous Showing 11-14 of 14 results.