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.

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A075186 Sixth column of triangle A075181 divided by 4!.

Original entry on oeis.org

5, 147, 3283, 67284, 1346625, 27061650, 553887180, 11636745120, 252045153360, 5641615980000, 130658463936000, 3132519418828800, 77747158404115200, 1997070421868121600, 53066619106300800000
Offset: 0

Views

Author

Wolfdieter Lang, Sep 19 2002

Keywords

Comments

Also sixth diagonal of unsigned A048594 triangle divided by 4!.

Crossrefs

Formula

a(n) = A075181(n+6, 5)/4! = |A048594(n+6, n+1)|/4!, n>=0.
a(n) = -(n+1)!*S1(n+6, n+1)/4! with S1(n, m) := A008275(n, m) (Stirling1).

A075187 Seventh column of triangle A075181 divided by 4!.

Original entry on oeis.org

30, 1089, 29531, 723680, 17084650, 400186050, 9447948510, 226861274640, 5570383618800, 140328075888000, 3634144257744000, 96862561213017600, 2658662147043302400, 75165608074100544000, 2188816503237524160000
Offset: 0

Views

Author

Wolfdieter Lang, Sep 19 2002

Keywords

Comments

Also seventh diagonal of triangle A048594 divided by 4!.

Crossrefs

Formula

a(n) = A075181(n+7, 6)/4! = |A048594(n+7, n+1)|/4!, n>=0.
a(n) = (n+1)!*S1(n+7, n+1)/4! with S1(n, m) := A008275(n, m) (Stirling1).

A308941 a(n) = Product_{k=1..n} |Stirling1(n,k)| * k!.

Original entry on oeis.org

1, 1, 2, 72, 114048, 14515200000, 234709539840000000, 698712561855933972480000000, 523145284340194421434020324704256000000, 128974285815375032145715297526239008267285037056000000, 13271794881195622862513637643190449698396346431150489600000000000000000
Offset: 0

Views

Author

Ilya Gutkovskiy, Jul 01 2019

Keywords

Crossrefs

Programs

  • Mathematica
    Table[Product[Abs[StirlingS1[n, k]] k!, {k, 1, n}], {n, 0, 10}]
  • PARI
    a(n) = prod(k=1, n, abs(stirling(n, k, 1))*k!); \\ Michel Marcus, Jul 02 2019

A322342 Expansion of e.g.f. 1/(1 - log(1 + x)/(1 - log(1 + x)^2/(1 - log(1 + x)^3/(1 - ...)))), a continued fraction.

Original entry on oeis.org

1, 1, 1, 8, 16, 224, 1328, 8280, 192960, 337992, 33969672, 11690832, 7909754400, -2553028752, 2357881048560, 3942533549568, 661635400722048, 13397372969553792, -107825500036658304, 22964754191590789632, -572404186520543904768, 31472786179436211417600, -886973046496642227294720
Offset: 0

Views

Author

Ilya Gutkovskiy, Dec 19 2018

Keywords

Crossrefs

Programs

  • Mathematica
    nmax = 22; CoefficientList[Series[1/(1 + ContinuedFractionK[-Log[1 + x]^k, 1, {k, 1, nmax}]), {x, 0, nmax}], x] Range[0, nmax]!

Formula

a(n) = Sum_{k=0..n} Stirling1(n,k)*A005169(k)*k!.

A225474 Triangle read by rows, k!*2^k*s_2(n, k) where s_m(n, k) are the Stirling-Frobenius cycle numbers of order m; n >= 0, k >= 0.

Original entry on oeis.org

1, 1, 2, 3, 8, 8, 15, 46, 72, 48, 105, 352, 688, 768, 384, 945, 3378, 7600, 11040, 9600, 3840, 10395, 39048, 97112, 167040, 193920, 138240, 46080, 135135, 528414, 1418648, 2754192, 3857280, 3736320, 2257920, 645120, 2027025, 8196480, 23393376, 49824768, 79892736
Offset: 0

Views

Author

Peter Luschny, May 19 2013

Keywords

Comments

The Stirling-Frobenius cycle numbers are defined in A225470.

Examples

			[n\k][ 0,    1,    2,     3,    4,    5]
[0]    1,
[1]    1,    2,
[2]    3,    8,    8,
[3]   15,   46,   72,    48,
[4]  105,  352,  688,   768,  384,
[5]  945, 3378, 7600, 11040, 9600, 3840.
		

Crossrefs

Programs

  • Mathematica
    SFCSO[n_, k_, m_] := SFCSO[n, k, m] = If[k>n || k<0, 0, If[n == 0 && k == 0, 1, m*k*SFCSO[n-1, k-1, m] + (m*n-1)*SFCSO[n-1, k, m]]]; Table[SFCSO[n, k, 2], {n, 0, 8}, {k, 0, n}] // Flatten (* Jean-François Alcover, Feb 05 2014, translated from Sage *)
  • Sage
    @CachedFunction
    def SF_CSO(n, k, m):
        if k > n or k < 0 : return 0
        if n == 0 and k == 0: return 1
        return m*k*SF_CSO(n-1, k-1, m) + (m*n-1)*SF_CSO(n-1, k, m)
    for n in (0..8): [SF_CSO(n, k, 2) for k in (0..n)]

Formula

For a recurrence see the Sage program.
T(n, 0) ~ A001147; T(n, n) ~ A000165; T(n, n-1) ~ A014479.
T(n,k) = A028338(n,k) * A000165(k) = A225475(n,k) * A000079(k) = A161198(n,k) * A000142(k). - Philippe Deléham, Jun 25 2015
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