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 1-6 of 6 results.

A027486 First column of triangle A027477, constructed from the Stirling numbers of the first kind.

Original entry on oeis.org

1, 3, 23, 330, 7604, 256620, 11923260, 729524880, 56840099904, 5493503695680, 644870893060800, 90366972897801600, 14899694352066120960, 2855250418022402400000, 629258349435218754451200, 158034681938560927788288000, 44866854739192779425625292800
Offset: 1

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Author

Keywords

Crossrefs

Cf. A027477 (Square of normalized Stirling matrix of the first kind).

Formula

a(n) = A027477(n,1).
a(n) = n!*Sum_{k=1..n} (-1)^(n-k)*Stirling1(n, k)/k. Sum_{n>=0} a(n)*x^n/n!^2 = -log(log(1-x))-Ei(1, log(1-x))-gamma. - Vladeta Jovovic, Jan 29 2005

Extensions

More terms from Sean A. Irvine, Nov 06 2019

A027481 Second subdiagonal of triangle A027477, constructed from the Stirling numbers of the first kind.

Original entry on oeis.org

23, 215, 1035, 3535, 9730, 23058, 48930, 95370, 173745, 299585, 493493, 782145, 1199380, 1787380, 2597940, 3693828, 5150235, 7056315, 9516815, 12653795, 16608438, 21542950, 27642550, 35117550, 44205525, 55173573, 68320665, 83980085, 102521960, 124355880
Offset: 3

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Author

Keywords

Crossrefs

Cf. A027477.

Formula

a(n) = A027477(n+2,n).
Conjectures from Chai Wah Wu, Apr 08 2021: (Start)
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) for n > 9.
G.f.: x^3*(-13*x^2 - 54*x - 23)/(x - 1)^7. (End)

Extensions

More terms from Sean A. Irvine, Nov 06 2019

A027487 Second column of triangle A027477, constructed from the Stirling numbers of the first kind.

Original entry on oeis.org

1, 12, 215, 5700, 212464, 10645152, 691560092, 56600396640, 5701663652256, 693513787887360, 100238236943757120, 16984716659427928320, 3334997046159250716672, 751255152802084700098560, 192454224298697834146195200, 55636762557552859712661811200
Offset: 2

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Author

Keywords

Crossrefs

Cf. A027477 (Square of normalized Stirling matrix of the first kind).

Formula

a(n) = A027477(n,2).

Extensions

More terms from Sean A. Irvine, Nov 06 2019

A027488 Third column of triangle A027477, constructed from the Stirling numbers of the first kind.

Original entry on oeis.org

1, 30, 1035, 45675, 2582209, 183962268, 16206744140, 1734708878100, 222083697846516, 33544055541553128, 5906505211210055088, 1199823052824417425040, 278598452852079082857744, 73346715446248518553100160, 21736011315987768499695624960
Offset: 3

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Author

Keywords

Crossrefs

Cf. A027477 (Square of normalized Stirling matrix of the first kind).

Formula

a(n) = A027477(n,3).

Extensions

More terms from Sean A. Irvine, Nov 06 2019

A027478 Triangle of the cube of the normalized, unsigned Stirling matrix of the first kind.

Original entry on oeis.org

1, 7, 1, 176, 39, 1, 10746, 2951, 126, 1, 1297704, 407450, 22535, 310, 1, 272866980, 94128364, 6139575, 112435, 645, 1, 91570835040, 33910601508, 2487385684, 54814095, 426475, 1197, 1, 46034917019280, 18030534782364, 1446119232796, 36402686929, 345710680, 1333906, 2044, 1
Offset: 1

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Keywords

Comments

The absolute values are unchanged if one uses the signed Stirling numbers of the first kind.

Examples

			The first rows of the triangle are :
  1,
  7, 1,
  176, 39, 1,
  10746, 2951, 126, 1,
  1297704, 407450, 22535, 310, 1,
  272866980, 94128364, 6139575, 112435, 645, 1,
  ...
		

Crossrefs

Cf. A027477 for the quadratic version.
Cf. A027479 for the quartic version.
Cf. A027482 is the first subdiagonal of this 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*Table[i!^3,{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!^3)).
T is the lower triangular matrix A.A.A.N.

Extensions

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

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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Author

Keywords

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
Showing 1-6 of 6 results.