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.

A027483 Second subdiagonal of triangle A027478, constructed from the Stirling numbers of the first kind.

Original entry on oeis.org

176, 2951, 22535, 112435, 426475, 1333906, 3614226, 8762370, 19439970, 40113425, 77924561, 143844701, 254168005, 432404980, 711642100, 1137438516, 1771335876, 2695062315, 4015516715, 5870624375, 8436160271, 11933641126, 16639392550, 22894902550, 31118577750
Offset: 3

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Author

Keywords

Crossrefs

Cf. A027478.

Formula

a(n) = A027478(n,n+2).
Conjectures from Chai Wah Wu, May 07 2025: (Start)
a(n) = 9*a(n-1) - 36*a(n-2) + 84*a(n-3) - 126*a(n-4) + 126*a(n-5) - 84*a(n-6) + 36*a(n-7) - 9*a(n-8) + a(n-9) for n > 11.
G.f.: x^3*(x^5 + 112*x^4 + 1072*x^3 + 2312*x^2 + 1367*x + 176)/(1 - x)^9. (End)

Extensions

More terms from Sean A. Irvine, Nov 06 2019

A027489 First column of Triangle A027478, constructed from Stirling numbers of the first kind.

Original entry on oeis.org

1, 7, 176, 10746, 1297704, 272866980, 91570835040, 46034917019280, 33038572997888640, 32591683412232799680, 42861143959833044563200, 73273310483627217731644800, 159431451667479363623304936960
Offset: 1

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Crossrefs

Cf. A027478 (Cube of normalized Stirling matrix of the first kind).

Formula

a(n) = A027478(n,1)

A027490 Second column of Triangle A027478, constructed from the Stirling numbers of the first kind.

Original entry on oeis.org

1, 39, 2951, 407450, 94128364, 33910601508, 18030534782364, 13546779499777104, 13886615636338251456, 18871622607827176957440, 33195072622146083265245760, 74062306101954993414777244800
Offset: 2

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Crossrefs

Cf. A027478 (Cube of normalized Stirling matrix of the first kind).

Formula

a(n) = A027478(n,2)

A027491 Third column of Triangle A027478, constructed from the Stirling numbers of the first kind.

Original entry on oeis.org

1, 126, 22535, 6139575, 2487385684, 1446119232796, 1166500896454844, 1267622549125064100, 1809397702962603426816, 3319681647209765132077992, 7683477487469739839805775776, 22073571178683618465281583731376
Offset: 3

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Author

Keywords

Crossrefs

Cf. A027478 (Cube of the normalized Stirling matrix of the first kind).

Formula

a(n) = A027478(n,3)

A027479 Triangle of the fourth power of the normalized, unsigned Stirling matrix of the first kind.

Original entry on oeis.org

1, 15, 1, 1175, 120, 1, 294330, 36935, 510, 1, 181082204, 25816200, 460035, 1560, 1, 231844265940, 36133755364, 757122975, 3411835, 3885, 1, 551220029003580, 91850446178400, 2159098539409, 11690792400, 18037810, 8400, 1, 2239429013789400720, 393327895035809180, 10088942720014620, 62324463343569, 117282133080, 75042450, 16380, 1
Offset: 1

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Examples

			First rows of the triangle are:
          1;
         15,        1;
       1175,      120,      1;
     294330,    36935,    510,    1;
  181082204, 25816200, 460035, 1560, 1;
  ...
		

Crossrefs

Cf. A027477 (second-order triangle), A027478 (third-order triangle).

Programs

  • Mathematica
    Module[{nmax=8,m},m=(Table[Table[(-1)^(i+j) StirlingS1[i,j]/i!,{j,1,nmax}],{i,1,nmax}]);m=m.m.m.m*Table[i!^4,{i,1,nmax}]; Flatten[Table[Table[m[[i,j]],{j,1,i}],{i,1,nmax}],1]]

Extensions

Definition, formula and program edited for clarity by Olivier Gérard, Jan 20 2019

A027477 Triangle of the square of the normalized, unsigned Stirling matrix of the first kind.

Original entry on oeis.org

1, 3, 1, 23, 12, 1, 330, 215, 30, 1, 7604, 5700, 1035, 60, 1, 256620, 212464, 45675, 3535, 105, 1, 11923260, 10645152, 2582209, 241080, 9730, 168, 1, 729524880, 691560092, 183962268, 19661649, 970200, 23058, 252, 1
Offset: 1

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Keywords

Examples

			First rows of the triangle are:
1,
3,1,
23,12,1,
330,215,30,1,
7604,5700,1035,60,1,
256620,212464,45675,3535,105,1
...
		

Crossrefs

Cf. A027478, A027479 (third and fourth power).

Programs

  • Mathematica
    Module[{nmax=8,m},m=(Table[Table[(-1)^(i+j) StirlingS1[i,j]/i!,{j,1,nmax}],{i,1,nmax}]);m=m.m*Table[i!^2,{i,1,nmax}]; Flatten[Table[Table[m[[i,j]],{j,1,i}],{i,1,nmax}],1]]

Formula

Let A be the lower triangular matrix with entries a[ i, j ] = (-1)^(i+j)*s(i, j)/i! if j<=i, 0 if j>i, where s(i,j) is the Stirling number of the first kind. Let N be the column vector ((i!^2)).
T is the lower triangular matrix A.A.N.

Extensions

Definition, formula and program edited for clarity by Olivier Gérard, Jan 20 2019

A027482 a(n) = n*(n^3 - 1)/2.

Original entry on oeis.org

7, 39, 126, 310, 645, 1197, 2044, 3276, 4995, 7315, 10362, 14274, 19201, 25305, 32760, 41752, 52479, 65151, 79990, 97230, 117117, 139909, 165876, 195300, 228475, 265707, 307314, 353626, 404985, 461745, 524272, 592944, 668151
Offset: 2

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Comments

Row sums in an n X n X n pandiagonal magic cube with entries (0..n^3-1).

Crossrefs

First subdiagonal of A027478 (Cube of a triangular matrix constructed from the Stirling numbers of the first kind).

Programs

  • Magma
    [n * (n^3 - 1)/2: n in [2..50]]; // Vincenzo Librandi, Dec 29 2012
  • Mathematica
    Table[(m^4 - m)/2, {m, 44}] (* Zerinvary Lajos, Mar 21 2007 *)
    CoefficientList[Series[(7 + 4*x + x^2)/(1 - x)^5, {x, 0, 40}], x] (* Vincenzo Librandi, Dec 29 2012 *)
  • PARI
    t(n)=n*(n+1)/2;
    for(n=0,50,print1(t(n^2)-t(n)","))
    

Formula

a(n) = A027478(n,n-1)
a(n) = A000217(n^2) - A000217(n). - Jon Perry, Jul 21 2003
a(n) = A058895(n)/2. - Zerinvary Lajos, Jan 28 2008
G.f.: x^2*(7 + 4*x + x^2)/(1 - x)^5. - Vincenzo Librandi, Dec 29 2012
a(n) = 5*a(n-1) - 10*a(n-2) + 10*a(n-3) - 5*a(n-4) + a(n-5) for n > 6. - Chai Wah Wu, Apr 08 2021
Showing 1-7 of 7 results.