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 1-7 of 7 results.

A090448 Fourth column (m=3) of triangle A090447.

Original entry on oeis.org

9, 96, 500, 1800, 5145, 12544, 27216, 54000, 99825, 174240, 290004, 463736, 716625, 1075200, 1572160, 2247264, 3148281, 4332000, 5865300, 7826280, 10305449, 13406976, 17250000, 21970000, 27720225, 34673184, 43022196, 52983000, 64795425, 78725120, 95065344
Offset: 3

Views

Author

Wolfdieter Lang, Dec 23 2003

Keywords

Crossrefs

Programs

  • Maple
    seq(mul(binomial(n,k),k=1..3),n=3..30); # Zerinvary Lajos, Dec 13 2007
  • Mathematica
    a[n_] := Product[Binomial[n, k], {k, 0, 3}]; Array[a, 30, 3] (* Amiram Eldar, Sep 08 2022 *)
    LinearRecurrence[{7,-21,35,-35,21,-7,1},{9,96,500,1800,5145,12544,27216},40] (* Harvey P. Dale, Jul 18 2025 *)

Formula

a(n) = A090447(n,3).
a(n) = (n^3*(n-1)^2*(n-2)^1)/(1!*2!*3!) for n >= 3.
From Colin Barker, Jan 21 2013: (Start)
a(n) = (n^6-4*n^5+5*n^4-2*n^3)/12.
G.f.: -x^3*(x^3+17*x^2+33*x+9)/(x-1)^7. (End)
a(n) = A000330(n-1)^2 - A000292(n-1)^2. - J. M. Bergot, May 02 2014
a(n) = 7*a(n-1)-21*a(n-2)+35*a(n-3)-35*a(n-4)+21*a(n-5)-7*a(n-6)+a(n-7). - Wesley Ivan Hurt, May 04 2021
From Amiram Eldar, Sep 08 2022: (Start)
Sum_{n>=3} 1/a(n) = 207/4 - 9*Pi^2/2 - 6*zeta(3).
Sum_{n>=3} (-1)^(n+1)/a(n) = 165/4 - Pi^2/4 - 48*log(2) - 9*zeta(3)/2. (End)

A090449 Fifth column (m=4) of triangle A090447.

Original entry on oeis.org

96, 2500, 27000, 180075, 878080, 3429216, 11340000, 32942250, 86248800, 207352860, 464199736, 978193125, 1956864000, 3741740800, 6876627840, 12202737156, 20988540000, 35103820500, 57249238200, 91254750895, 142462526976, 218212500000, 328451500000, 486489948750
Offset: 4

Views

Author

Wolfdieter Lang, Dec 23 2003

Keywords

Crossrefs

Cf. A090447.

Programs

  • Mathematica
    LinearRecurrence[{11,-55,165,-330,462,-462,330,-165,55,-11,1},{96,2500,27000,180075,878080,3429216,11340000,32942250,86248800,207352860,464199736},40] (* Harvey P. Dale, Apr 10 2018 *)

Formula

a(n)= A090447(n, 4)= (n^4*(n-1)^3*(n-2)^2*(n-3)^1)/(1!*2!*3!*4!), n>=4.
G.f.: -x^4*(x^6+109*x^5+1435*x^4+4735*x^3+4780*x^2+1444*x+96)/(x-1)^11. - Colin Barker, Jan 21 2013
From Amiram Eldar, Sep 08 2022: (Start)
Sum_{n>=4} 1/a(n) = 700*Pi^2/9 + 4*Pi^4/15 - 40*zeta(3) - 20129/27.
Sum_{n>=4} (-1)^n/a(n) = 30311/27 - 26*Pi^2/9 - 7*Pi^4/30 - 11008*log(2)/9 - 186*zeta(3). (End)

A090450 Row sums of triangle A090447.

Original entry on oeis.org

1, 2, 5, 22, 221, 5556, 352897, 56909000, 23456163817, 24862388706622, 68125408037874461, 484697617517152241192, 8987761653844408528516645, 435751632681268773059903563592, 55389930392445599773550918556967161
Offset: 0

Views

Author

Wolfdieter Lang, Dec 23 2003

Keywords

Crossrefs

Cf. A090451 (alternating row sums).

Formula

a(n)=sum(A090447(n, m), m=0..n), n>=0.

A090451 Alternating row sums of triangle A090447.

Original entry on oeis.org

1, 0, 1, -2, 21, -454, 25285, -3606504, 1328522713, -1270747453940, 3169192850406441, -20676520009454537480, 353872602524737587995341, -15925173912641846013871947522, 1888348697181821236021540428910349, -591053910458037676348857289166882470064
Offset: 0

Views

Author

Wolfdieter Lang, Dec 23 2003

Keywords

Formula

a(n)=sum(A090447(n, m)*(-1)^m, m=0..n), n>=0.
A090450 (row sums).

A120409 a(n) = n^1*(n+1)^2*(n+2)^3*(n+3)^4*(n+4)^5*(n+5)^6/(1!*2!*3!*4!*5!*6!).

Original entry on oeis.org

162000, 26471025, 1376829440, 36294822144, 600112800000, 7031325609000, 63117561830400, 457937132487120, 2790771598030416, 14702257341646875, 68449036271616000, 286552568263270400, 1093771338292039680, 3849852478998931776, 12612749124441600000
Offset: 1

Views

Author

Zerinvary Lajos, Jul 05 2006

Keywords

Crossrefs

Programs

  • Maple
    [seq(n^1*(n+1)^2*(n+2)^3*(n+3)^4*(n+4)^5*(n+5)^6/(1!*2!*3!*4!*5!*6!),n=1..27)];
  • Mathematica
    Table[(Times@@Table[(n+k)^(k+1),{k,0,5}])/Times@@(Range[6]!),{n,15}] (* Harvey P. Dale, Jun 07 2022 *)
  • Sage
    [binomial(n,1)*binomial(n,3)*binomial(n,5)*binomial(n,2)*binomial(n,4)*binomial(n,6) for n in range(6, 19)] # Zerinvary Lajos, May 17 2009

Formula

Sum_{n>=1} 1/a(n) = 789878089*Pi^2/18000 + 64687*Pi^4/150 - 16*Pi^6/21 + 6603436*zeta(3)/25 + 80136*zeta(5) - 56698539425671/64800000. - Amiram Eldar, Sep 08 2022

Extensions

Offset changed from 0 to 1 by Georg Fischer, May 08 2021

A120408 a(n) = n^1*(n+1)^2*(n+2)^3*(n+3)^4*(n+4)^5/(1!*2!*3!*4!*5!).

Original entry on oeis.org

2500, 162000, 3781575, 49172480, 432081216, 2857680000, 15219319500, 68309049600, 266863130820, 929327871472, 2937513954375, 8547581952000, 23153892070400, 58918947333120, 141893427649968, 325406324160000, 714327643354500, 1507601438758800, 3070631112865855
Offset: 1

Views

Author

Zerinvary Lajos, Jul 05 2006

Keywords

Crossrefs

Programs

  • Maple
    [seq(n^1*(n+1)^2*(n+2)^3*(n+3)^4*(n+4)^5/(1!*2!*3!*4!*5!),n=1..37)];
  • Mathematica
    Table[n^1*(n+1)^2*(n+2)^3*(n+3)^4*(n+4)^5/(1!*2!*3!*4!*5!),{n,19}] (* James C. McMahon, Oct 05 2024 *)

Extensions

Offset changed from 0 to 1 by Georg Fischer, May 08 2021
a(17)-a(19) from James C. McMahon, Oct 05 2024

A120410 a(n) = n^1*(n+1)^2*(n+2)^3*(n+3)^4*(n+4)^5*(n+5)^6*(n+6)^7/(1!*2!*3!*4!*5!*6!*7!).

Original entry on oeis.org

0, 26471025, 11014635520, 1306613597184, 72013536000000, 2320337450970000, 49989108969676800, 785820119347897920, 9577928124440387712, 94609025993497640625, 783056974947287040000, 5572874347584082739200, 34808179069805870776320, 193986366711798174329088
Offset: 0

Views

Author

Zerinvary Lajos, Jul 05 2006

Keywords

Crossrefs

Programs

  • Maple
    [seq(n^1*(n+1)^2*(n+2)^3*(n+3)^4*(n+4)^5*(n+5)^6*(n+6)^7/(1!*2!*3!*4!*5!*6!*7!),n=1..17)];
  • Mathematica
    Table[n*(n+1)^2*(n+2)^3*(n+3)^4*(n+4)^5*(n+5)^6*(n+6)^7/(1!*2!*3!*4!*5!*6!*7!), {n, 0, 10}] (* Amiram Eldar, Sep 08 2022 *)

Formula

Sum_{n>=1} 1/a(n) = 422971791896349857/972000000 - 845737633741*Pi^2/22500 - 230834541*Pi^4/500 - 58492*Pi^6/15 - 18320341039*zeta(3)/1800 - 15501934*zeta(5)/5 - 5040*zeta(7). - Amiram Eldar, Sep 08 2022

Extensions

a(0) prepended by Amiram Eldar, Sep 08 2022
Showing 1-7 of 7 results.