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.

User: Takao Komatsu

Takao Komatsu's wiki page.

Takao Komatsu has authored 40 sequences. Here are the ten most recent ones:

A219247 Denominators of poly-Cauchy numbers of the second kind hat c_n^(2).

Original entry on oeis.org

1, 4, 36, 48, 1800, 240, 35280, 20160, 226800, 50400, 3659040, 665280, 1967565600, 2242240, 129729600, 34594560, 2677989600, 66830400, 1857684628800, 39109150080, 3226504881600, 307286179200, 2333316585600, 1285014931200, 2192556726360000, 25057791158400
Offset: 0

Author

Takao Komatsu, Mar 31 2013

Keywords

Comments

The poly-Cauchy numbers of the second kind hat c_n^(k) can be expressed in terms of the (unsigned) Stirling numbers of the first kind: hat c_n^(k) = (-1)^n*sum(abs(stirling1(n,m))/(m+1)^k, m=0..n).

Crossrefs

Cf. A002790, A223899, A224102 (numerators).

Programs

  • Mathematica
    Table[Denominator[Sum[StirlingS1[n, k] (-1)^k/ (k + 1)^2, {k, 0, n}]], {n, 0, 25}]
  • PARI
    a(n) = denominator(sum(k=0, n, stirling(n, k, 1)*(-1)^k/(k+1)^2)); \\ Michel Marcus, Nov 14 2015

A224094 Denominators of poly-Cauchy numbers c_n^(2).

Original entry on oeis.org

1, 4, 36, 48, 1800, 720, 35280, 20160, 226800, 10080, 731808, 665280, 1967565600, 11211200, 129729600, 34594560, 18745927200, 28641600, 371536925760, 3990729600, 3226504881600, 4877558400, 466663317120, 550720684800, 2192556726360000, 175404538108800
Offset: 0

Author

Takao Komatsu, Mar 30 2013

Keywords

Comments

The poly-Cauchy numbers c_n^k can be expressed in terms of the (unsigned) Stirling numbers of the first kind: c_n^(k) = (-1)^n*sum(abs(stirling1(n,m))*(-1)^m/(m+1)^k, m=0..n).

Crossrefs

Cf. A006233, A222627, A224095 (numerators).

Programs

  • Mathematica
    Table[Denominator[Sum[StirlingS1[n, k]/ (k + 1)^2, {k, 0, n}]], {n, 0, 25}]
  • PARI
    a(n) = denominator(sum(k=0, n,stirling(n, k, 1)/(k+1)^2)); \\ Michel Marcus, Nov 15 2015

A224107 Denominators of poly-Cauchy numbers of the second kind hat c_n^(5).

Original entry on oeis.org

1, 32, 7776, 82944, 388800000, 155520000, 2613824640000, 11948912640000, 3629482214400000, 806551603200000, 77937565348177920000, 14170466426941440000, 92074412343521441433600000, 524640526173911347200000, 6070840374298117017600000, 12951126131835982970880000
Offset: 0

Author

Takao Komatsu, Mar 31 2013

Keywords

Comments

The poly-Cauchy numbers of the second kind hat c_n^(k) can be expressed in terms of the (unsigned) Stirling numbers of the first kind: hat c_n^(k) = (-1)^n*sum(abs(stirling1(n,m))/(m+1)^k, m=0..n).

Crossrefs

Cf. A002790, A223904, A219247, A224103, A224105, A224109 (numerators).

Programs

  • Mathematica
    Table[Denominator[Sum[StirlingS1[n, k] (-1)^k/ (k + 1)^5, {k, 0, n}]], {n, 0, 25}]
  • PARI
    a(n) = denominator(sum(k=0, n,(-1)^k*stirling(n, k, 1)/(k+1)^5)); \\ Michel Marcus, Nov 15 2015

Extensions

More terms from Michel Marcus, Nov 15 2015

A224097 Numerators of poly-Cauchy numbers c_n^(3).

Original entry on oeis.org

1, 1, -19, 89, -46261, 23323, -114895757, 760567603, -174446569403, 302339104957, -2125170096355349, 3788248001789087, -1573899862241140688567, 317684785943639774839, -2242333884754953400123
Offset: 0

Author

Takao Komatsu, Mar 31 2013

Keywords

Comments

The poly-Cauchy numbers c_n^(k) can be expressed in terms of the (unsigned) Stirling numbers of the first kind: c_n^(k) = (-1)^n*sum(abs(stirling1(n,m))*(-1)^m/(m+1)^k, m=0..n).

Crossrefs

Cf. A006232, A222636, A224095, A224096 (denominators).

Programs

  • Mathematica
    Table[Numerator[Sum[StirlingS1[n, k]/ (k + 1)^3, {k, 0, n}]], {n, 0, 25}]
  • PARI
    a(n) = numerator(sum(k=0, n,stirling(n, k, 1)/(k+1)^3)); \\ Michel Marcus, Nov 15 2015

A224096 Denominators of poly-Cauchy numbers c_n^(3).

Original entry on oeis.org

1, 8, 216, 576, 108000, 14400, 14817600, 16934400, 571536000, 127008000, 101428588800, 18441561600, 709031939616000, 12120204096000, 6678479808000, 24932991283200, 229679599076928000, 818822100096000
Offset: 0

Author

Takao Komatsu, Mar 31 2013

Keywords

Comments

The poly-Cauchy numbers c_n^(k) can be expressed in terms of the (unsigned) Stirling numbers of the first kind: c_n^(k) = (-1)^n*sum(abs(stirling1(n,m))*(-1)^m/(m+1)^k, m=0..n).

Crossrefs

Cf. A006233, A222636, A224094, A224097 (numerators).

Programs

  • Mathematica
    Table[Denominator[Sum[StirlingS1[n, k]/ (k + 1)^3, {k, 0, n}]], {n, 0, 25}]
  • PARI
    a(n) = denominator(sum(k=0, n, stirling(n, k, 1)/(k+1)^3)); \\ Michel Marcus, Nov 15 2015

A224105 Denominators of poly-Cauchy numbers of the second kind hat c_n^(4).

Original entry on oeis.org

1, 16, 1296, 6912, 6480000, 288000, 6223392000, 14224896000, 1440270720000, 64012032000, 562320096307200, 511200087552000, 255506749760021760000, 1455878916011520000, 673863955411046400, 17969705477627904000
Offset: 0

Author

Takao Komatsu, Mar 31 2013

Keywords

Comments

The poly-Cauchy numbers of the second kind hat c_n^(k) can be expressed in terms of the (unsigned) Stirling numbers of the first kind: hat c_n^(k) = (-1)^n*sum(abs(stirling1(n,m))/(m+1)^k, m=0..n).

Crossrefs

Cf. A002790, A223902, A219247, A224103, A224106 (numerators).

Programs

  • Mathematica
    Table[Denominator[Sum[StirlingS1[n, k] (-1)^k/ (k + 1)^4, {k, 0, n}]], {n, 0, 25}]
  • PARI
    a(n) = denominator(sum(k=0, n,(-1)^k*stirling(n, k, 1)/(k+1)^4)); \\ Michel Marcus, Nov 15 2015

A224098 Denominators of poly-Cauchy numbers c_n^(4).

Original entry on oeis.org

1, 16, 1296, 6912, 6480000, 2592000, 6223392000, 14224896000, 1440270720000, 320060160000, 2811600481536000, 511200087552000, 255506749760021760000, 291175783202304000, 16846598885276160000
Offset: 0

Author

Takao Komatsu, Mar 31 2013

Keywords

Comments

The poly-Cauchy numbers c_n^(k) can be expressed in terms of the (unsigned) Stirling numbers of the first kind: c_n^(k) = (-1)^n*sum(abs(stirling1(n,m))*(-1)^m/(m+1)^k, m=0..n).

Crossrefs

Cf. A006233, A222748, A224094, A224096, A224099 (numerators).

Programs

  • Mathematica
    Table[Denominator[Sum[StirlingS1[n, k]/ (k + 1)^4, {k, 0, n}]], {n, 0, 25}]
  • PARI
    a(n) = denominator(sum(k=0, n,stirling(n, k, 1)/(k+1)^4)); \\ Michel Marcus, Nov 15 2015

A224106 Numerators of poly-Cauchy numbers of the second kind hat c_n^(4).

Original entry on oeis.org

1, -1, 97, -1147, 3472243, -653983, 74118189437, -1058923294571, 777910456216513, -285577840060819, 23240203016832136201, -216925341603548096639, 1222007019804929270080450811
Offset: 0

Author

Takao Komatsu, Mar 31 2013

Keywords

Comments

The poly-Cauchy numbers of the second kind hat c_n^(k) can be expressed in terms of the (unsigned) Stirling numbers of the first kind: hat c_n^(k) = (-1)^n*sum(abs(stirling1(n,m))/(m+1)^k, m=0..n).

Crossrefs

Cf. A002657, A223902, A224105, A114102, A224104, A224105 (denominators).

Programs

  • Mathematica
    Table[Numerator[Sum[StirlingS1[n, k] (-1)^k/ (k + 1)^4, {k, 0, n}]], {n, 0,
      25}]
  • PARI
    a(n) = numerator(sum(k=0, n,(-1)^k*stirling(n, k, 1)/(k+1)^4)); \\ Michel Marcus, Nov 15 2015

A224104 Numerators of poly-Cauchy numbers of the second kind hat c_n^(3).

Original entry on oeis.org

1, -1, 35, -217, 135989, -236881, 435876493, -3174551347, 790667708347, -1473406853309, 11050163107919893, -20886680047664287, 9154917271574968829623, -277315386220087376401, 803143323197313772705
Offset: 0

Author

Takao Komatsu, Mar 31 2013

Keywords

Comments

The poly-Cauchy numbers of the second kind hat c_n^(k) can be expressed in terms of the (unsigned) Stirling numbers of the first kind: hat c_n^(k) = (-1)^n*sum(abs(stirling1(n,m))/(m+1)^k, m=0..n).

Crossrefs

Cf. A002657, A223901, A224102, A224103 (denominators).

Programs

  • Mathematica
    Table[Numerator[Sum[StirlingS1[n, k] (-1)^k/ (k + 1)^3, {k, 0, n}]], {n, 0,
      25}]
  • PARI
    a(n) = numerator(sum(k=0, n, stirling(n, k, 1)*(-1)^k/(k+1)^3)); \\ Michel Marcus, Nov 14 2015

A224109 Numerators of poly-Cauchy numbers of the second kind hat c_n^(5).

Original entry on oeis.org

1, -1, 275, -6289, 92902541, -154473289, 13399738273333, -377635608584803, 822223497000264427, -1492945924219675973, 1323386773861946436609781, -2448418399924413951578983, 177825546947844845937070681472647
Offset: 0

Author

Takao Komatsu, Mar 31 2013

Keywords

Comments

The poly-Cauchy numbers of the second kind hat c_n^(k) can be expressed in terms of the (unsigned) Stirling numbers of the first kind: hat c_n^(k) = (-1)^n*sum(abs(stirling1(n,m))/(m+1)^k, m=0..n).

Crossrefs

Programs

  • Mathematica
    Table[Numerator[Sum[StirlingS1[n, k] (-1)^k/ (k + 1)^5, {k, 0, n}]], {n, 0, 25}]
  • PARI
    a(n) = numerator(sum(k=0, n,(-1)^k*stirling(n, k, 1)/(k+1)^5)); \\ Michel Marcus, Nov 15 2015