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 1-9 of 9 results.

A263031 Decimal expansion of a constant related to A262877 and A262947 (negated).

Original entry on oeis.org

0, 1, 4, 5, 3, 7, 4, 2, 9, 1, 8, 3, 2, 8, 4, 0, 3, 3, 6, 0, 5, 0, 2, 0, 2, 9, 4, 5, 0, 2, 2, 6, 2, 0, 9, 0, 3, 6, 0, 5, 4, 1, 4, 9, 7, 5, 9, 3, 4, 6, 4, 4, 4, 1, 3, 8, 1, 5, 2, 2, 4, 7, 4, 0, 5, 5, 3, 4, 6, 9, 2, 7, 4, 4, 9, 5, 5, 0, 0, 8, 3, 1, 2, 5, 9, 0, 7, 2, 3, 8, 9, 0, 1, 2, 7, 7, 0, 9, 8, 8, 3, 6, 0, 5, 4, 4
Offset: 0

Views

Author

Vaclav Kotesovec, Oct 08 2015

Keywords

Examples

			-0.01453742918328403360502029450226209036054149759346444138152247405534...
		

Crossrefs

Programs

  • Mathematica
    NIntegrate[1/x*(Exp[-x]/(1 - Exp[-3*x])^2 - 1/(9*x^2) - 2/(9*x) - 5*Exp[-x]/36), {x, 0, Infinity}, WorkingPrecision -> 120, MaxRecursion -> 100, PrecisionGoal -> 110]

Formula

Integral_{x=0..infinity} 1/x*(exp(-x)/(1 - exp(-3*x))^2 - 1/(9*x^2) - 2/(9*x) - 5*exp(-x)/36) dx.
exp(3*(A263030+A263031)) = A^2 * Gamma(1/3) / (3^(11/12) * exp(1/6) * sqrt(2*Pi)), where A = A074962 is the Glaisher-Kinkelin constant.

A262877 Expansion of Product_{k>=1} 1/(1-x^(3*k-2))^k.

Original entry on oeis.org

1, 1, 1, 1, 3, 3, 3, 6, 9, 9, 13, 19, 23, 28, 42, 51, 62, 84, 108, 127, 170, 219, 261, 328, 427, 512, 632, 807, 987, 1190, 1504, 1838, 2214, 2744, 3374, 4036, 4950, 6060, 7260, 8793, 10748, 12853, 15459, 18766, 22473, 26834, 32425, 38768, 46136, 55376, 66168
Offset: 0

Views

Author

Vaclav Kotesovec, Oct 04 2015

Keywords

Comments

a(n) is the number of partitions of n into parts 3*k-2 of k kinds (k>=1). - Joerg Arndt, Oct 06 2015

Crossrefs

Programs

  • Maple
    with(numtheory):
    a:= proc(n) option remember; `if`(n=0, 1, add(add(d*
          `if`(irem(d+3, 3, 'r')=1, r, 0), d=divisors(j))*a(n-j), j=1..n)/n)
        end:
    seq(a(n), n=0..60);  # Alois P. Heinz, Oct 05 2015
  • Mathematica
    nmax=100; CoefficientList[Series[Product[1/(1-x^(3k-2))^k, {k, 1, nmax}], {x, 0, nmax}], x]
    nmax=100; CoefficientList[Series[E^Sum[1/j*x^j/(1-x^(3j))^2,{j,1,nmax}],{x,0,nmax}],x]

Formula

a(n) ~ Zeta(3)^(13/108) * exp(d2 - Pi^4 / (972*Zeta(3)) + Pi^2 * n^(1/3) / (2^(1/3) * 3^(7/3) * Zeta(3)^(1/3)) + 3^(1/3) * Zeta(3)^(1/3) * n^(2/3) / 2^(2/3)) / (2^(41/108) * 3^(20/27) * sqrt(Pi) * n^(67/108)), where d2 = A263031 = Integral_{x=0..infinity} 1/x*(exp(-x)/(1 - exp(-3*x))^2 - 1/(9*x^2) - 2/(9*x) - 5*exp(-x)/36) = -0.0145374291832840336050202945022620903605414975934644413815... . - Vaclav Kotesovec, Oct 08 2015

A262946 Expansion of Product_{k>=1} 1/(1-x^(3*k-1))^(3*k-1).

Original entry on oeis.org

1, 0, 2, 0, 3, 5, 4, 10, 13, 15, 37, 31, 61, 87, 99, 178, 228, 286, 477, 552, 816, 1163, 1418, 2077, 2790, 3507, 5113, 6478, 8563, 11888, 15005, 20100, 27054, 34055, 46002, 59905, 76436, 102105, 130879, 168103, 221954, 281300, 363743, 472557, 597579, 772148
Offset: 0

Views

Author

Vaclav Kotesovec, Oct 05 2015

Keywords

Comments

A262946(n)/A262947(n) ~ exp(3*(d1-d2)) * Gamma(1/3)^3 / (2*Pi)^(3/2), where d1 = A263030 and d2 = A263031. - Vaclav Kotesovec, Oct 08 2015

Crossrefs

Programs

  • Maple
    with(numtheory):
    a:= proc(n) option remember; `if`(n=0, 1, add(add(d*
          `if`(irem(d+3, 3, 'r')=2, 3*r-1, 0),
           d=divisors(j))*a(n-j), j=1..n)/n)
        end:
    seq(a(n), n=0..45);  # Alois P. Heinz, Oct 05 2015
  • Mathematica
    nmax=60; CoefficientList[Series[Product[1/((1-x^(3k-1))^(3k-1)),{k,1,nmax}],{x,0,nmax}],x]
    nmax=60; CoefficientList[Series[E^Sum[1/j*x^(2*j)*(2+x^(3*j))/(1-x^(3*j))^2, {j, 1, nmax}], {x, 0, nmax}], x]

Formula

a(n) ~ (2*Zeta(3))^(5/36) * exp(3*d1 + (3/2)^(2/3) * Zeta(3)^(1/3) * n^(2/3)) / (3^(29/36) * Gamma(2/3) * n^(23/36)), where d1 = A263030 = Integral_{x=0..infinity} 1/x*(exp(-2*x)/(1 - exp(-3*x))^2 - 1/(9*x^2) - 1/(9*x) + exp(-x)/36) = -0.18870819197952853237641009864920797359211446726842922150941... . - Vaclav Kotesovec, Oct 08 2015

A262923 Expansion of Product_{k>=1} 1 / ((1-x^(3*k-1))^(3*k-1) * (1-x^(3*k-2))^(3*k-2)).

Original entry on oeis.org

1, 1, 3, 3, 10, 15, 27, 44, 79, 128, 211, 331, 549, 843, 1338, 2061, 3195, 4851, 7384, 11104, 16696, 24774, 36817, 54173, 79560, 116067, 168880, 244293, 352480, 506012, 724531, 1032762, 1468271, 2079525, 2937102, 4134399, 5804795, 8124459, 11342952, 15791650
Offset: 0

Views

Author

Vaclav Kotesovec, Oct 04 2015

Keywords

Comments

Convolution of A262946 and A262947.

Crossrefs

Programs

  • Mathematica
    nmax=60; CoefficientList[Series[Product[1/((1 - x^(3*k-1))^(3*k-1) * (1 - x^(3*k-2))^(3*k-2)), {k, 1, nmax}], {x, 0, nmax}], x]

Formula

a(n) ~ exp(-1/6 + 3^(2/3)*(Zeta(3)/2)^(1/3) * n^(2/3)) * A^2 * Zeta(3)^(1/9) / (2^(5/18) * 3^(31/36) * sqrt(Pi) * n^(11/18)), where Zeta(3) = A002117 and A = A074962 is the Glaisher-Kinkelin constant.

A263030 Decimal expansion of a constant related to A262876 and A262946 (negated).

Original entry on oeis.org

1, 8, 8, 7, 0, 8, 1, 9, 1, 9, 7, 9, 5, 2, 8, 5, 3, 2, 3, 7, 6, 4, 1, 0, 0, 9, 8, 6, 4, 9, 2, 0, 7, 9, 7, 3, 5, 9, 2, 1, 1, 4, 4, 6, 7, 2, 6, 8, 4, 2, 9, 2, 2, 1, 5, 0, 9, 4, 1, 7, 4, 3, 3, 7, 8, 2, 3, 2, 3, 7, 2, 1, 3, 7, 1, 8, 0, 6, 7, 4, 7, 1, 3, 9, 4, 6, 9, 7, 4, 1, 6, 1, 8, 7, 0, 1, 6, 2, 5, 8, 3, 2, 8, 1, 7, 9
Offset: 0

Views

Author

Vaclav Kotesovec, Oct 08 2015

Keywords

Examples

			-0.18870819197952853237641009864920797359211446726842922150941743378232...
		

Crossrefs

Programs

  • Mathematica
    NIntegrate[1/x*(Exp[-2*x]/(1 - Exp[-3*x])^2 - 1/(9*x^2) - 1/(9*x) + Exp[-x]/36), {x, 0, Infinity}, WorkingPrecision -> 120, MaxRecursion -> 100, PrecisionGoal -> 110]

Formula

Integral_{x=0..infinity} 1/x*(exp(-2*x)/(1 - exp(-3*x))^2 - 1/(9*x^2) - 1/(9*x) + exp(-x)/36) dx.
exp(3*(A263030+A263031)) = A^2 * Gamma(1/3) / (3^(11/12) * exp(1/6) * sqrt(2*Pi)), where A = A074962 is the Glaisher-Kinkelin constant.

A285048 Expansion of Product_{k>=0} 1/(1-x^(4*k+1))^(4*k+1).

Original entry on oeis.org

1, 1, 1, 1, 1, 6, 6, 6, 6, 15, 30, 30, 30, 43, 88, 123, 123, 140, 250, 385, 455, 476, 678, 1098, 1413, 1564, 1913, 2918, 4048, 4707, 5452, 7572, 10747, 13265, 15195, 19534, 27349, 35146, 41042, 50011, 67596, 88897, 106519, 126635, 164230, 216862, 266473, 314883
Offset: 0

Views

Author

Seiichi Manyama, Apr 15 2017

Keywords

Crossrefs

Product_{k>=0} 1/(1-x^(m*k+1))^(m*k+1): A262811 (m=2), A262947 (m=3), this sequence (m=4), A285049 (m=5).

Programs

  • Mathematica
    nmax = 50; CoefficientList[Series[Product[1/(1-x^(4*k-3))^(4*k-3), {k,1,nmax}], {x,0,nmax}], x] (* Vaclav Kotesovec, Apr 16 2017 *)

Formula

a(n) ~ 4 * Pi * 2^(25/72) * Zeta(3)^(11/72) * exp(4*c + 3 * 2^(-4/3) * Zeta(3)^(1/3) * n^(2/3)) / (sqrt(3) * Gamma(1/4)^3 * n^(47/72)), where c = Integral_{x=0..inf} ((-19/(exp(x)*96) + 1/(exp(x)*(1 - exp(-4*x))^2) - 1/(16*x^2) - 3/(16*x))/x) dx = 0.09601010361866957956805888476415949391295401812706635... - Vaclav Kotesovec, Apr 16 2017

A285050 Expansion of Product_{k>=0} (1-x^(3*k+1))^(3*k+1).

Original entry on oeis.org

1, -1, 0, 0, -4, 4, 0, -7, 13, -6, -10, 38, -32, -9, 74, -103, 27, 137, -266, 153, 191, -593, 537, 167, -1161, 1437, -222, -2035, 3397, -1578, -3110, 7160, -5285, -3712, 13942, -13920, -2002, 24848, -32241, 6764, 40661, -68059, 32487, 59109, -133506, 95221, 71243
Offset: 0

Views

Author

Seiichi Manyama, Apr 15 2017

Keywords

Crossrefs

Product_{k>=0} (1-x^(m*k+1))^(m*k+1): A285069 (m=2), this sequence (m=3), A285070 (m=4), A285071 (m=5).
Cf. A262947.

A285049 Expansion of Product_{k>=0} 1/(1-x^(5*k+1))^(5*k+1).

Original entry on oeis.org

1, 1, 1, 1, 1, 1, 7, 7, 7, 7, 7, 18, 39, 39, 39, 39, 55, 121, 177, 177, 177, 198, 360, 591, 717, 717, 743, 1045, 1777, 2393, 2645, 2676, 3199, 4982, 7264, 8650, 9148, 9956, 13760, 20348, 26060, 28873, 30869, 38134, 54634, 73142, 85536, 92302, 106501, 143167
Offset: 0

Views

Author

Seiichi Manyama, Apr 15 2017

Keywords

Comments

In general, if m >= 1 and g.f. = Product_{k>=1} 1/(1-x^(m*k-m+1))^(m*k-m+1), then a(n, m) ~ exp(c*m + 3 * 2^(-2/3) * m^(-1/3) * Zeta(3)^(1/3) * n^(2/3)) * 2^(19*m/36 + 1/(6*m) - 1) * m^(17*m/36 + 5/(6*m) - 3/2) * Pi^(m/2 - 1) * Zeta(3)^(1/(6*m) + m/36) / (sqrt(3) * Gamma(1/m)^(m-1) * n^(1/2 + 1/(6*m) + m/36)), where c = Integral_{x=0..infinity} exp((2*m-1)*x) / (x*(exp(m*x) - 1)^2) + (1/12 - (m-1)^2/(2*m^2))/(x*exp(x)) - 1/(m^2*x^3) - (m-1)/(m^2*x^2) dx. - Vaclav Kotesovec, Apr 17 2017

Crossrefs

Product_{k>=0} 1/(1-x^(m*k+1))^(m*k+1): A000219 (m=1), A262811 (m=2), A262947 (m=3), A285048 (m=4), this sequence (m=5).
Cf. A285071.

Programs

  • Mathematica
    nmax = 50; CoefficientList[Series[Product[1/(1-x^(5*k-4))^(5*k-4), {k,1,nmax}], {x,0,nmax}], x] (* Vaclav Kotesovec, Apr 16 2017 *)

Formula

a(n) ~ 2^(301/180) * 5^(37/36) * Pi^(3/2) * Zeta(3)^(31/180) * exp(5*c + 3 * 2^(-2/3) * 5^(-1/3) * Zeta(3)^(1/3) * n^(2/3)) / (sqrt(3) * Gamma(1/5)^4 * n^(121/180)), where c = Integral_{x=0..inf} ((-71/(exp(x)*300) + 1/(exp(x)*(1 - exp(-5*x))^2) - 1/(25*x^2) - 4/(25*x))/x) dx = 0.186382690624752630391368364629918483384424086341764409146923686... - Vaclav Kotesovec, Apr 16 2017

A362696 Expansion of e.g.f. Product_{k>0} (1 - x^(3*k-2))^(-1/(3*k-2)).

Original entry on oeis.org

1, 1, 2, 6, 30, 150, 900, 7020, 62460, 562140, 5984280, 67252680, 863165160, 11700148680, 173098134000, 2625661170000, 45310413258000, 782198417206800, 14310269286746400, 280333959468789600, 6002139207488767200, 129820528515538159200, 2934651197018947982400
Offset: 0

Views

Author

Seiichi Manyama, Jul 07 2023

Keywords

Crossrefs

Programs

  • PARI
    my(N=30, x='x+O('x^N)); Vec(serlaplace(1/prod(k=1,N, (1-x^(3*k-2))^(1/(3*k-2)))))

Formula

a(0) = 1; a(n) = (n-1)! * Sum_{k=1..n} A001817(k) * a(n-k)/(n-k)!.
Showing 1-9 of 9 results.