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 1-4 of 4 results.

A300703 Number of compositions (ordered partitions) of n into prime parts that do not divide n.

Original entry on oeis.org

1, 0, 0, 0, 0, 2, 0, 5, 2, 5, 2, 19, 2, 45, 6, 10, 14, 231, 4, 500, 14, 48, 45, 2351, 12, 1520, 144, 637, 100, 24441, 6, 53242, 810, 2558, 1294, 15402, 94, 550862, 3707, 16658, 680, 2616337, 53, 5701552, 11639, 6606, 30749, 27077004, 800, 21212965, 5215, 611097, 109818, 280237216
Offset: 0

Views

Author

Ilya Gutkovskiy, Mar 11 2018

Keywords

Examples

			a(9) = 5 because we have [7, 2], [5, 2, 2], [2, 7], [2, 5, 2] and [2, 2, 5].

Links

Crossrefs

Cf. A000040, A023360, A128515, A209402, A284463, A300702, A300704, A300706.

Programs

  • Maple
    a:= proc(m) option remember; local b; b:= proc(n) option
      remember; `if`(n=0, 1, add(`if`(not isprime(j) or
       irem(m, j)=0, 0, b(n-j)), j=2..n)) end; b(m)
    end:
seq(a(n), n=0..80);  # Alois P. Heinz, Mar 11 2018
  • Mathematica
    Table[SeriesCoefficient[1/(1 - Sum[Boole[Mod[n, k] != 0 && PrimeQ[k]] x^k, {k, 1, n}]), {x, 0, n}], {n, 0, 53}]

A300584 Number of partitions of n into distinct prime power parts (not including 1) that do not divide n.

Original entry on oeis.org

1, 0, 0, 0, 0, 1, 0, 2, 1, 2, 1, 4, 1, 5, 2, 4, 3, 8, 2, 11, 4, 6, 6, 18, 3, 13, 10, 10, 8, 35, 7, 42, 9, 20, 24, 22, 10, 72, 33, 35, 11, 102, 21, 120, 29, 26, 65, 161, 16, 117, 56, 93, 52, 246, 43, 113, 36, 139, 160, 370, 39, 422, 208, 102, 62, 216, 110, 613, 145, 305, 130, 780, 57, 878
Offset: 0

Views

Author

Ilya Gutkovskiy, Mar 09 2018

Keywords

Examples

			a(9) = 2 because we have [7, 2] and [5, 4].

Links

Crossrefs

Cf. A054685, A200745, A209402, A246655, A300580.

Programs

  • Mathematica
    Table[SeriesCoefficient[Product[(1 + Boole[Mod[n, k] != 0 && PrimePowerQ[k]] x^k), {k, 1, n}], {x, 0, n}], {n, 0, 73}]

A300586 Number of partitions of n into distinct squarefree parts that do not divide n.

Original entry on oeis.org

1, 0, 0, 0, 0, 1, 0, 1, 1, 1, 1, 2, 1, 4, 2, 2, 4, 6, 2, 8, 4, 6, 6, 15, 4, 11, 10, 12, 8, 30, 3, 38, 24, 17, 24, 23, 14, 70, 36, 37, 23, 102, 8, 122, 49, 39, 80, 177, 38, 136, 54, 113, 101, 297, 60, 152, 102, 192, 226, 485, 28, 571, 312, 200, 390, 338, 84, 908, 393, 507, 104, 1229, 241, 1421
Offset: 0

Views

Author

Ilya Gutkovskiy, Mar 09 2018

Keywords

Examples

			a(14) = 2 because we have [11, 3] and [6, 5, 3].

Links

Crossrefs

Cf. A005117, A087188, A200745, A209402, A225245, A300584, A300585.

Programs

  • Mathematica
    Table[SeriesCoefficient[Product[(1 + Boole[Mod[n, k] != 0 && SquareFreeQ[k]] x^k), {k, 1, n}], {x, 0, n}], {n, 0, 73}]

A294142 Number of partitions of n into distinct odd parts that do not divide n.

Original entry on oeis.org

1, 0, 0, 0, 0, 0, 0, 0, 1, 0, 1, 0, 1, 0, 2, 0, 3, 1, 2, 2, 3, 0, 4, 4, 4, 2, 6, 1, 6, 8, 4, 10, 12, 4, 12, 5, 7, 17, 17, 8, 14, 24, 9, 29, 24, 4, 33, 40, 25, 29, 28, 23, 45, 63, 23, 30, 52, 37, 84, 99, 26, 113, 112, 23, 143, 60, 57, 173, 143, 89, 70, 226, 87, 256, 256, 53, 245, 135, 127, 378, 233
Offset: 0

Views

Author

Ilya Gutkovskiy, Oct 23 2017

Keywords

Examples

			a(14) = 2 because we have [11, 3] and [9, 5].

Links

Crossrefs

Cf. A000700, A098743, A171565, A200745, A209402, A294141.

Programs

  • Mathematica
    Table[SeriesCoefficient[Product[1 + Boole[Mod[n, k] > 0 && OddQ[k]] x^k, {k, 1, n}], {x, 0, n}], {n, 0, 80}]
Showing 1-4 of 4 results.

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