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 1-5 of 5 results.

A281083 Expansion of Product_{k>=0} (1 + x^(5*k*(k+1)/2+1)).

Original entry on oeis.org

1, 1, 0, 0, 0, 0, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 0, 0, 0, 0, 1, 1, 0, 0, 0, 0, 0, 0, 0, 1, 1, 0, 0, 0, 0, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 0, 0, 1, 1, 1, 1, 0, 0, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 0, 0, 0, 0, 1, 1, 0, 1, 1, 0, 0, 0, 0, 2, 2, 0, 0, 0, 0, 1, 1, 0, 0, 1, 1, 0, 0, 0, 0, 2, 2, 0, 0, 0, 0, 1, 1
Offset: 0

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Author

Ilya Gutkovskiy, Jan 14 2017

Keywords

Comments

Number of partitions of n into distinct centered pentagonal numbers (A005891).

Examples

			a(82) = 2 because we have [76, 6] and [51, 31].
		

Crossrefs

Programs

  • Mathematica
    nmax = 105; CoefficientList[Series[Product[1 + x^(5 k (k + 1)/2 + 1), {k, 0, nmax}], {x, 0, nmax}], x]

Formula

G.f.: Product_{k>=0} (1 + x^(5*k*(k+1)/2+1)).

A281081 Expansion of Product_{k>=0} (1 + x^(3*k*(k+1)/2+1)).

Original entry on oeis.org

1, 1, 0, 0, 1, 1, 0, 0, 0, 0, 1, 1, 0, 0, 1, 1, 0, 0, 0, 1, 1, 0, 0, 1, 1, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 1, 1, 0, 0, 1, 2, 1, 0, 0, 2, 2, 0, 0, 1, 1, 1, 1, 0, 0, 2, 2, 0, 0, 2, 3, 1, 0, 1, 2, 1, 0, 0, 0, 1, 2, 1, 1, 2, 2, 1, 1, 1, 1, 1, 1, 1, 2, 2, 1, 1, 1, 1, 1, 1, 2, 3, 2, 1, 2, 3, 1, 0, 0, 1, 2
Offset: 0

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Author

Ilya Gutkovskiy, Jan 14 2017

Keywords

Comments

Number of partitions of n into distinct centered triangular numbers (A005448).

Examples

			a(46) = 2 because we have [46] and [31, 10, 4, 1].
		

Crossrefs

Programs

  • Mathematica
    nmax = 105; CoefficientList[Series[Product[1 + x^(3 k (k + 1)/2 + 1), {k, 0, nmax}], {x, 0, nmax}], x]

Formula

G.f.: Product_{k>=0} (1 + x^(3*k*(k+1)/2+1)).

A281084 Expansion of Product_{k>=0} (1 + x^(3*k*(k+1)+1)).

Original entry on oeis.org

1, 1, 0, 0, 0, 0, 0, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 0, 0, 0, 0, 0, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 0, 0, 0, 0, 0, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 0, 0, 0, 1, 1, 1, 1, 0, 0, 0, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 0, 0, 0, 0, 0, 1, 1, 0, 0, 1, 1, 0, 0, 0, 0, 0, 2, 2, 0, 0, 0, 0, 0, 1
Offset: 0

Views

Author

Ilya Gutkovskiy, Jan 14 2017

Keywords

Comments

Number of partitions of n into distinct centered hexagonal numbers (A003215).

Examples

			a(98) = 2 because we have [91, 7] and [61, 37].
		

Crossrefs

Programs

  • Mathematica
    nmax = 105; CoefficientList[Series[Product[1 + x^(3 k (k + 1) + 1), {k, 0, nmax}], {x, 0, nmax}], x]

Formula

G.f.: Product_{k>=0} (1 + x^(3*k*(k+1)+1)).

A350204 a(n) is the smallest positive integer which can be represented as the sum of distinct centered square numbers in exactly n ways, or 0 if no such integer exists.

Original entry on oeis.org

1, 66, 127, 151, 277, 212, 296, 325, 404, 332, 373, 440, 452, 458, 445, 464, 530, 505, 586, 572, 553, 578, 525, 637, 613, 632, 625, 626, 650, 692, 674, 638, 705, 686, 734, 710, 698, 789, 777, 745, 771, 817, 794, 746, 850, 770, 758, 847, 972, 908
Offset: 1

Views

Author

Ilya Gutkovskiy, Dec 19 2021

Keywords

Crossrefs

A332006 Number of compositions (ordered partitions) of n into distinct centered square numbers.

Original entry on oeis.org

1, 1, 0, 0, 0, 1, 2, 0, 0, 0, 0, 0, 0, 1, 2, 0, 0, 0, 2, 6, 0, 0, 0, 0, 0, 1, 2, 0, 0, 0, 2, 6, 0, 0, 0, 0, 0, 0, 2, 6, 0, 1, 2, 6, 24, 0, 2, 6, 0, 0, 0, 0, 0, 0, 2, 6, 0, 0, 0, 6, 24, 1, 2, 0, 0, 0, 4, 12, 0, 0, 0, 6, 24, 0, 2, 6, 0, 0, 0, 12, 48, 0, 0, 0, 24, 121, 4, 6
Offset: 0

Views

Author

Ilya Gutkovskiy, Feb 04 2020

Keywords

Examples

			a(19) = 6 because we have [13, 5, 1], [13, 1, 5], [5, 13, 1], [5, 1, 13], [1, 13, 5] and [1, 5, 13].
		

Crossrefs

Showing 1-5 of 5 results.