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.

A356269 a(n) = Sum_{k=0..n} binomial(2*k, k) * p(k), where p(k) is the partition function A000041.

Original entry on oeis.org

1, 3, 15, 75, 425, 2189, 12353, 63833, 346973, 1805573, 9565325, 49069517, 257289529, 1307750129, 6723491129, 34024174649, 172873744739, 865954792079, 4359881882579, 21679061144579, 108108834714719, 534409071271199, 2642716232918639, 12975671796056639, 63765647596939139
Offset: 0

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Author

Vaclav Kotesovec, Aug 01 2022

Keywords

Crossrefs

Programs

  • Mathematica
    Table[Sum[Binomial[2*k, k] * PartitionsP[k], {k, 0, n}], {n, 0, 30}]

Formula

a(n) ~ binomial(2*n,n) * p(n) * 4/3.
a(n) ~ 2^(2*n) * exp(Pi*sqrt(2*n/3)) / (3^(3/2) * sqrt(Pi) * n^(3/2)).

A356287 a(n) = Sum_{k=0..n} binomial(3*k, k) * q(k), where q(k) is the number of partitions into distinct parts (A000009).

Original entry on oeis.org

1, 4, 19, 187, 1177, 10186, 84442, 665842, 5078668, 42573268, 343023418, 2665464058, 21440629558, 167644287550, 1330569327310, 10641989818078, 82797155054782, 644097780350332, 5102709814966162, 39499844158337962, 307777892529889642, 2406854983109480302
Offset: 0

Views

Author

Vaclav Kotesovec, Aug 01 2022

Keywords

Crossrefs

Programs

  • Mathematica
    Table[Sum[Binomial[3*k, k] * PartitionsQ[k], {k, 0, n}], {n, 0, 30}]

Formula

a(n) ~ 3^(3*n + 13/4) * exp(Pi*sqrt(n/3)) / (23 * sqrt(Pi) * n^(5/4) * 2^(2*n+3)).

A367101 a(n) = Sum_{k=0..n} A000108(k) * A000009(k).

Original entry on oeis.org

1, 2, 4, 14, 42, 168, 696, 2841, 11421, 50317, 218277, 923709, 4043889, 17416089, 76253769, 338014584, 1469460024, 6395962044, 28367342244, 123799554504, 543903261384, 2403339554904, 10545287718864, 46223487538464, 203591793511992, 893988182518176, 3924601439423256
Offset: 0

Views

Author

Vaclav Kotesovec, Nov 04 2023

Keywords

Crossrefs

Programs

  • Mathematica
    Table[Sum[CatalanNumber[k]*PartitionsQ[k], {k, 0, n}], {n, 0, 30}]

Formula

a(n) ~ 2^(2*n) * exp(Pi*sqrt(n/3)) / (3^(5/4) * sqrt(Pi) * n^(9/4)).
Showing 1-3 of 3 results.