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 1-3 of 3 results.

A035695 Number of partitions of n into parts 8k+4 and 8k+6 with at least one part of each type.

Original entry on oeis.org

0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 1, 0, 1, 0, 3, 0, 1, 0, 4, 0, 3, 0, 7, 0, 4, 0, 10, 0, 8, 0, 15, 0, 11, 0, 21, 0, 18, 0, 30, 0, 24, 0, 42, 0, 37, 0, 56, 0, 50, 0, 78, 0, 70, 0, 102, 0, 95, 0, 137, 0, 129, 0, 179, 0, 171, 0, 236, 0, 227, 0, 303, 0, 297, 0, 395, 0, 386, 0, 502, 0
Offset: 1

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Keywords

Crossrefs

Bisections give A035626 (even part), A000004 (odd part).

Programs

  • Mathematica
    nmax = 83; s1 = Range[0, nmax/8]*8 + 4; s2 = Range[0, nmax/8]*8 + 6;
    Table[Count[IntegerPartitions[n, All, s1~Join~s2],
    x_ /; ContainsAny[x, s1 ] && ContainsAny[x, s2 ]], {n, 1, nmax}] (* Robert Price, Aug 16 2020 *)
    nmax = 83; l = Rest@CoefficientList[Series[(-1 + 1/Product[(1 - x^(8 k + 4)), {k, 0, nmax}])*(-1 + 1/Product[(1 - x^(8 k + 6)), {k, 0, nmax}]), {x, 0, nmax}], x]  (* Robert Price, Aug 16 2020*)

Formula

G.f.: (-1 + 1/Product_{k>=0} (1 - x^(8 k + 4)))*(-1 + 1/Product_{k>=0} (1 - x^(8 k + 6))). - Robert Price, Aug 16 2020

A035693 Number of partitions of n into parts 8k+3 and 8k+7 with at least one part of each type.

Original entry on oeis.org

0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 1, 0, 0, 1, 1, 2, 1, 1, 2, 1, 1, 3, 3, 4, 3, 3, 5, 3, 4, 7, 7, 8, 7, 8, 10, 8, 10, 15, 14, 15, 16, 16, 20, 18, 21, 29, 27, 28, 32, 33, 36, 37, 42, 51, 50, 52, 59, 60, 66, 69, 77, 90, 88, 93, 105, 107, 115, 124, 135, 152, 153, 160, 180, 183, 195
Offset: 1

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Author

Keywords

Crossrefs

Programs

  • Mathematica
    nmax = 77; s1 = Range[0, nmax/8]*8 + 3; s2 = Range[0, nmax/8]*8 + 7;
    Table[Count[IntegerPartitions[n, All, s1~Join~s2],
    x_ /; ContainsAny[x, s1 ] && ContainsAny[x, s2 ]], {n, 1, nmax}] (* Robert Price, Aug 15 2020 *)
    nmax = 77; l = Rest@CoefficientList[Series[(-1 + 1/Product[(1 - x^(8 k + 3)), {k, 0, nmax}])*(-1 + 1/Product[(1 - x^(8 k + 7)), {k, 0, nmax}]), {x, 0, nmax}], x]  (* Robert Price, Aug 15 2020*)

Formula

G.f.: (-1 + 1/Product_{k>=0} (1 - x^(8 k + 3)))*(-1 + 1/Product_{k>=0} (1 - x^(8 k + 7))). - Robert Price, Aug 15 2020

A035463 Number of partitions of n into parts 8k+4 or 8k+5.

Original entry on oeis.org

0, 0, 0, 1, 1, 0, 0, 1, 1, 1, 0, 2, 2, 1, 1, 2, 3, 2, 1, 4, 4, 3, 2, 5, 7, 5, 3, 7, 9, 8, 5, 9, 13, 11, 8, 13, 17, 16, 12, 18, 24, 22, 17, 24, 32, 31, 24, 32, 43, 42, 34, 43, 56, 57, 47, 57, 74, 75, 64, 76, 96, 100, 86, 99, 126, 130, 115, 129, 161, 171, 151, 168, 207, 219, 200
Offset: 1

Views

Author

Keywords

Crossrefs

Cf. A035694.

Programs

  • Mathematica
    nmax = 100; Rest[CoefficientList[Series[Product[1/((1 - x^(8k+4))*(1 - x^(8k+5))), {k, 0, nmax}], {x, 0, nmax}], x]] (* Vaclav Kotesovec, Aug 27 2015 *)
    nmax = 60; kmax = nmax/8;
    s = Flatten[{Range[0, kmax]*8 + 4}~Join~{Range[0, kmax]*8 + 5}];
    Table[Count[IntegerPartitions@n, x_ /; SubsetQ[s, x]], {n, 1, nmax}] (* Robert Price, Aug 04 2020 *)

Formula

a(n) ~ exp(Pi*sqrt(n/6)) * Gamma(5/8) / (4 * 2^(9/16) * 3^(5/16) * Pi^(3/8) * n^(13/16)). - Vaclav Kotesovec, Aug 27 2015
Showing 1-3 of 3 results.