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 1-10 of 11 results. Next

A066989 a(n) = (n!)^3 * Sum_{i=1..n} 1/i^3.

Original entry on oeis.org

1, 9, 251, 16280, 2048824, 444273984, 152759224512, 78340747014144, 57175952894078976, 57223737619918848000, 76212579497951858688000, 131758938842553681444864000, 289584291977410916858462208000, 794860754824699647616459210752000
Offset: 1

Views

Author

Benoit Cloitre, Jan 27 2002

Keywords

Comments

p^2 divides a(p-1) for prime p>5. - Alexander Adamchuk, Jul 11 2006

Crossrefs

Cf. A007408.
Column k=3 of A291556.

Programs

  • Mathematica
    f[k_] := k^3; t[n_] := Table[f[k], {k, 1, n}]
    a[n_] := SymmetricPolynomial[n - 1, t[n]]
    Table[a[n], {n, 1, 22}] (* A066989 *)
    (* Clark Kimberling, Dec 29 2011 *)
    Table[(n!)^3 * Sum[1/i^3, {i, 1, n}], {n, 1, 20}] (* Vaclav Kotesovec, Aug 27 2017 *)

Formula

Recurrence: a(1) = 1, a(2) = 9, a(n+2) = (2*n+3)*(n^2+3*n+3)*a(n+1) - (n+1)^6*a(n). b(n) = n!^3 satisfies the same recurrence with the initial conditions b(1) = 1, b(2) = 8. Hence we obtain the finite continued fraction expansion a(n)/b(n) = 1/(1-1^6/(9-2^6/(35-3^6/(91-...-(n-1)^6/((2n-1)*(n^2-n+1)))))) for n >= 2, leading to the infinite continued fraction expansion zeta(3) = 1/(1-1^6/(9-2^6/(35-3^6/(91-...-(n-1)^6/((2n-1)*(n^2-n+1)-...))))). Compare with A001819. - Peter Bala, Jul 19 2008
a(n) ~ Zeta(3) * (2*Pi)^(3/2) * n^(3*n+3/2) / exp(3*n). - Vaclav Kotesovec, Aug 27 2017
Sum_{n>=1} a(n) * x^n / (n!)^3 = polylog(3,x) / (1 - x). - Ilya Gutkovskiy, Jul 14 2020

A099827 Generalized harmonic number H(n,5) = Sum_{k=1..n} 1/k^5 multiplied by (n!)^5.

Original entry on oeis.org

0, 1, 33, 8051, 8252000, 25795462624, 200610400564224, 3371852494046112768, 110492114540967125581824, 6524555433591956305924325376, 652461835742417609568446054400000, 105080260346474296336209157187174400000
Offset: 0

Views

Author

Alexander Adamchuk, Oct 27 2004

Keywords

Comments

Note that a(n) is divisible by n, except when n is prime. Also, a(n+1) is divisible by n, except when n is prime or n = 0.

Examples

			a(2) = (2!)^5 * (1 + 1/2^5) = 2^5 + 1 = 33,
a(3) = (3!)^5 * (1 + 1/2^5 + 1/3^5) = 6^5 + 3^5 + 1 = 8051.
		

Crossrefs

Column k = 5 of A291556.

Programs

  • Mathematica
    Table[(n!)^5*Sum[1/k^5, {k, 1, n}], {n, 0, 13}] or Table[(n!)^5*HarmonicNumber[n, 5], {n, 0, 13}]

Formula

a(n) = (n!)^5 * Sum_{k=1..n} 1/k^5 = (n!)^5 * HarmonicNumber[n, 5] = (n!)^5 * A099828(n)/A069052(n).
a(0) = 0, a(1) = 1, a(n+1) = (n^5 + (n+1)^5)*a(n) - n^10*a(n-1) for n > 0. - Seiichi Manyama, Aug 24 2017
a(n) ~ Zeta(5) * (2*Pi)^(5/2) * n^(5*n+5/2) / exp(5*n). - Vaclav Kotesovec, Aug 27 2017
Sum_{n>=0} a(n) * x^n / (n!)^5 = polylog(5,x) / (1 - x). - Ilya Gutkovskiy, Jul 14 2020

Extensions

a(0) = 0 prepended by Seiichi Manyama, Aug 23 2017
Name edited by Petros Hadjicostas, May 10 2020

A291456 a(n) = (n!)^6 * Sum_{i=1..n} 1/i^6.

Original entry on oeis.org

0, 1, 65, 47449, 194397760, 3037656102976, 141727869124448256, 16674281388691716870144, 4371079210518164503303028736, 2322975003299339366419974718488576, 2322977286679362958150790503464960000000
Offset: 0

Views

Author

Seiichi Manyama, Aug 24 2017

Keywords

Crossrefs

Column k=6 of A291556.
Cf. A000254 (k=1), A001819 (k=2), A066989 (k=3), A203229 (k=4), A099827 (k=5).

Programs

  • Mathematica
    Table[(n!)^6 * Sum[1/i^6, {i, 1, n}], {n, 0, 15}] (* Vaclav Kotesovec, Aug 27 2017 *)

Formula

a(0) = 0, a(1) = 1, a(n+1) = (n^6 + (n+1)^6)*a(n) - n^12*a(n-1) for n > 0.
a(n) ~ 8 * Pi^9 * n^(6*n+3) / (945 * exp(6*n)). - Vaclav Kotesovec, Aug 27 2017
a(n) = (n!)^6 * A103345(n)/A103346(n). - Petros Hadjicostas, May 10 2020
Sum_{n>=0} a(n) * x^n / (n!)^6 = polylog(6,x) / (1 - x). - Ilya Gutkovskiy, Jul 15 2020

A291505 a(n) = (n!)^7 * Sum_{i=1..n} 1/i^7.

Original entry on oeis.org

0, 1, 129, 282251, 4624680320, 361307736471424, 101143400834944548864, 83296040059942781485105152, 174684539610200377980575079727104, 835510910973061065615656036610946891776, 8355109938323553617123838798161699143680000000
Offset: 0

Views

Author

Seiichi Manyama, Aug 25 2017

Keywords

Crossrefs

Cf. A000254 (k=1), A001819 (k=2), A066989 (k=3), A099827 (k=5), A291456 (k=6), this sequence (k=7), A291506 (k=8), A291507 (k=9), A291508 (k=10).
Column k=7 of A291556.

Programs

  • Mathematica
    Table[(n!)^7 * Sum[1/i^7, {i, 1, n}], {n, 0, 15}] (* Vaclav Kotesovec, Aug 27 2017 *)
  • PARI
    a(n) = n!^7*sum(i=1, n, 1/i^7); \\ Michel Marcus, Aug 26 2017

Formula

a(0) = 0, a(1) = 1, a(n+1) = (n^7+(n+1)^7)*a(n) - n^14*a(n-1) for n > 0.
a(n) ~ zeta(7) * (2*Pi)^(7/2) * n^(7*n+7/2) / exp(7*n). - Vaclav Kotesovec, Aug 27 2017
Sum_{n>=0} a(n) * x^n / (n!)^7 = polylog(7,x) / (1 - x). - Ilya Gutkovskiy, Jul 15 2020

A291506 a(n) = (n!)^8 * Sum_{i=1..n} 1/i^8.

Original entry on oeis.org

0, 1, 257, 1686433, 110523752704, 43173450975314176, 72514862031522895036416, 418033821374598847702425993216, 7013444132843374500928464765799366656, 301905779820559925981495987360836056017534976
Offset: 0

Views

Author

Seiichi Manyama, Aug 25 2017

Keywords

Crossrefs

Cf. A000254 (k=1), A001819 (k=2), A066989 (k=3), A099827 (k=5), A291456 (k=6), A291505 (k=7), this sequence (k=8), A291507 (k=9), A291508 (k=10).
Column k=8 of A291556.

Programs

  • Mathematica
    Table[(n!)^8 * Sum[1/i^8, {i, 1, n}], {n, 0, 15}] (* Vaclav Kotesovec, Aug 27 2017 *)
  • PARI
    a(n) = n!^8*sum(i=1, n, 1/i^8); \\ Michel Marcus, Aug 26 2017

Formula

a(0) = 0, a(1) = 1, a(n+1) = (n^8+(n+1)^8)*a(n) - n^16*a(n-1) for n > 0.
a(n) ~ 8 * Pi^12 * n^(8*n+4) / (4725 * exp(8*n)). - Vaclav Kotesovec, Aug 27 2017
Sum_{n>=0} a(n) * x^n / (n!)^8 = polylog(8,x) / (1 - x). - Ilya Gutkovskiy, Jul 15 2020

A291507 a(n) = (n!)^9 * Sum_{i=1..n} 1/i^9.

Original entry on oeis.org

0, 1, 513, 10097891, 2647111616000, 5170142516807540224, 52103129720841632885243904, 2102549272223560776918400601161728, 282199388424234851655058321255905292713984, 109329825340451764123791003609208862665771818418176
Offset: 0

Views

Author

Seiichi Manyama, Aug 25 2017

Keywords

Crossrefs

Cf. A000254 (k=1), A001819 (k=2), A066989 (k=3), A099827 (k=5), A291456 (k=6), A291505 (k=7), A291506 (k=8), this sequence (k=9), A291508 (k=10).
Column k=9 of A291556.

Programs

  • Mathematica
    Table[(n!)^9 * Sum[1/i^9, {i, 1, n}], {n, 0, 12}] (* Vaclav Kotesovec, Aug 27 2017 *)
  • PARI
    a(n) = n!^9*sum(i=1, n, 1/i^9); \\ Michel Marcus, Aug 26 2017

Formula

a(0) = 0, a(1) = 1, a(n+1) = (n^9+(n+1)^9)*a(n) - n^18*a(n-1) for n > 0.
a(n) ~ zeta(9) * (2*Pi)^(9/2) * n^(9*n+9/2) / exp(9*n). - Vaclav Kotesovec, Aug 27 2017
Sum_{n>=0} a(n) * x^n / (n!)^9 = polylog(9,x) / (1 - x). - Ilya Gutkovskiy, Jul 15 2020

A291508 a(n) = (n!)^10 * Sum_{i=1..n} 1/i^10.

Original entry on oeis.org

0, 1, 1025, 60526249, 63466432537600, 619789443653380965376, 37476298202061058687475122176, 10586126703664512292193022557971021824, 11366767006463449393869821987386636472445566976, 39633465899293694663690352980684333029782095493517541376
Offset: 0

Views

Author

Seiichi Manyama, Aug 25 2017

Keywords

Crossrefs

Cf. A000254 (k=1), A001819 (k=2), A066989 (k=3), A099827 (k=5), A291456 (k=6), A291505 (k=7), A291506 (k=8), A291507 (k=9), this sequence (k=10).
Column k=10 of A291556.

Programs

  • Mathematica
    Table[(n!)^10 * Sum[1/i^10, {i, 1, n}], {n, 0, 12}] (* Vaclav Kotesovec, Aug 27 2017 *)
  • PARI
    a(n) = n!^10*sum(i=1, n, 1/i^10); \\ Michel Marcus, Aug 26 2017

Formula

a(0) = 0, a(1) = 1, a(n+1) = (n^10+(n+1)^10)*a(n) - n^20*a(n-1) for n > 0.
a(n) ~ 32 * Pi^15 * n^(10*n+5) / (93555 * exp(10*n)). - Vaclav Kotesovec, Aug 27 2017
Sum_{n>=0} a(n) * x^n / (n!)^10 = polylog(10,x) / (1 - x). - Ilya Gutkovskiy, Jul 15 2020

A060943 a(n) = n!^n * Sum_{k=1..n} 1/k^n.

Original entry on oeis.org

1, 5, 251, 357904, 25795462624, 141727869124448256, 83296040059942781485105152, 7013444132843374500928464765799366656, 109329825340451764123791003609208862665771818418176, 396334659032531033249146049131230887376087800711479296000000000000
Offset: 1

Views

Author

Leroy Quet, May 07 2001

Keywords

Examples

			a(3) = 6^3 *(1 + 1/2^3 + 1/3^3) = 251.
		

Crossrefs

Cf. A036740.
Main diagonal of A291556.

Programs

  • Magma
    [(Factorial(n))^n*(&+[1/j^n: j in [1..n]]): n in [1..15]]; // G. C. Greubel, Apr 09 2021
    
  • Maple
    A060943:= n-> (n!)^n*add(1/j^n, j=1..n); seq(A060943(n), n=1..15); # G. C. Greubel, Apr 09 2021
  • Mathematica
    Table[(n!)^n * Sum[1/i^n, {i, 1, n}], {n, 1, 10}] (* Vaclav Kotesovec, Aug 27 2017 *)
  • PARI
    { default(realprecision, 100); for (n=1, 30, write("b060943.txt", n, " ", n!^n * sum(k=1, n, 1/k^n)); ) } \\ Harry J. Smith, Jul 14 2009
    
  • Sage
    [(factorial(n))^n*sum(1/j^n for j in (1..n)) for n in (1..15)] # G. C. Greubel, Apr 09 2021

Formula

a(n) ~ 2^(n/2) * Pi^(n/2) * n^(n*(2*n+1)/2) / exp(n^2 - 1/12). - Vaclav Kotesovec, Aug 27 2017
a(n) = (n!)^n * [x^n] PolyLog(n,x)/(1 - x), where PolyLog() is the polylogarithm function. - Ilya Gutkovskiy, Nov 27 2017

A203229 (n-1)-st elementary symmetric function of (1,16,...,n^4).

Original entry on oeis.org

1, 17, 1393, 357904, 224021776, 290539581696, 697854274212096, 2859056348455305216, 18760911610508623282176, 187626456226399005573120000, 2747212346823835568109649920000, 56968733990900457398848318341120000
Offset: 1

Views

Author

Clark Kimberling, Dec 30 2011

Keywords

Crossrefs

Column k=4 of A291556.

Programs

  • Mathematica
    f[k_] := k^4; t[n_] := Table[f[k], {k, 1, n}]
    a[n_] := SymmetricPolynomial[n - 1, t[n]]
    Table[a[n], {n, 1, 14}]     (* A203229 *)
    Table[(n!)^4 * Sum[1/i^4, {i, 1, n}], {n, 1, 20}] (* Vaclav Kotesovec, Aug 27 2017 *)

Formula

a(n) ~ 2 * Pi^6 * n^(4*n+2) / (45*exp(4*n)). - Vaclav Kotesovec, Aug 27 2017
Sum_{n>=1} a(n) * x^n / (n!)^4 = polylog(4,x) / (1 - x). - Ilya Gutkovskiy, Jul 14 2020

A291656 Square array T(n,k), n>=0, k>=0, read by antidiagonals: T(n,k) = ((2n-1)!!)^k * Sum_{i=1..n} 1/(2*i-1)^k.

Original entry on oeis.org

0, 0, 1, 0, 1, 2, 0, 1, 4, 3, 0, 1, 10, 23, 4, 0, 1, 28, 259, 176, 5, 0, 1, 82, 3527, 12916, 1689, 6, 0, 1, 244, 51331, 1213136, 1057221, 19524, 7, 0, 1, 730, 762743, 123296356, 885533769, 128816766, 264207, 8, 0, 1, 2188, 11406979, 12820180976, 809068942341, 1179489355164, 21878089479, 4098240, 9
Offset: 0

Views

Author

Seiichi Manyama, Aug 28 2017

Keywords

Examples

			Square array begins:
  0,   0,     0,       0,         0, ...
  1,   1,     1,       1,         1, ...
  2,   4,    10,      28,        82, ...
  3,  23,   259,    3527,     51331, ...
  4, 176, 12916, 1213136, 123296356, ...
		

Crossrefs

Columns k=0-5 give: A001477, A004041(n+1), A001824(n+1), A291585, A291586, A291587.
Rows n=0-2 give: A000004, A000012, A034472.
Main diagonal gives A291676.
Cf. A291556.

Formula

T(0,k) = 0, T(1,k) = 1 and T(n+1, k) = ((2*n-1)^k+(2*n+1)^k) * T(n, k) - (2*n-1)^(2*k) * T(n-1, k).
Showing 1-10 of 11 results. Next