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 1-7 of 7 results.

A279278 Expansion of Product_{k>=1} (1 + x^(k*(k+1)*(k+2)/6)).

Original entry on oeis.org

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

Views

Author

Ilya Gutkovskiy, Dec 09 2016

Keywords

Comments

Number of partitions of n into distinct tetrahedral numbers (A000292).

Examples

			a(35) = 2 because we have [35] and [20, 10, 4, 1].
		

Crossrefs

Cf. A000292, A007294, A024940, A068980, A350205 (positions of records).

Programs

  • Mathematica
    nmax=120; CoefficientList[Series[Product[1 + x^(k (k + 1) (k + 2)/6), {k, 1, nmax}], {x, 0, nmax}], x]

Formula

G.f.: Product_{k>=1} (1 + x^(k*(k+1)*(k+2)/6)).

A350210 a(n) is the smallest positive integer which can be represented as the sum of distinct nonzero n-gonal pyramidal numbers in exactly n ways, or 0 if no such integer exists.

Original entry on oeis.org

140, 490, 1055, 1872, 2610, 4255, 5011, 8708, 7497, 10819, 12860, 15636, 18055, 24275, 27373, 28146, 30826, 38178, 41849, 44025, 36165, 47621, 57896, 64648, 60064, 67125, 71975, 81820, 77701, 91584, 91320, 99835, 98916, 108686, 112606, 123180, 120919, 142270
Offset: 3

Views

Author

Ilya Gutkovskiy, Dec 19 2021

Keywords

Examples

			For n = 3: 140 = 1 + 20 + 35 + 84 = 56 + 84 = 20 + 120. - _Martin Ehrenstein_, Jan 09 2022
		

Crossrefs

Extensions

a(35)-a(40) from Martin Ehrenstein, Jan 09 2022

A350206 a(n) is the smallest positive integer which can be represented as the sum of distinct nonzero square pyramidal numbers in exactly n ways, or 0 if no such integer exists.

Original entry on oeis.org

1, 91, 300, 490, 580, 525, 810, 910, 1100, 1050, 1330, 1340, 1430, 1400, 1625, 1750, 1540, 1700, 1820, 1955, 2010, 1995, 1980, 1925, 2185, 2280, 2190, 2275, 2360, 2535, 2445, 2415, 2505, 2500, 2605, 2645, 2640, 2785, 2780, 2865, 2870, 2925, 2800, 2835, 2940
Offset: 1

Views

Author

Ilya Gutkovskiy, Dec 19 2021

Keywords

Crossrefs

A360214 a(n) is the smallest positive integer which can be represented as the sum of distinct nonzero octahedral numbers in exactly n ways, or -1 if no such integer exists.

Original entry on oeis.org

1, 231, 575, 721, 1618, 1750, 1877, 2240, 2736, 2995, 3105, 3080, 3500, 3311, 3920, 4151, 4280, 4495, 4719, 4621, 4675, 5041, 5164, 5291, 5060, 5591, 5480, 5566, 5635, 5755, 5985, 6216, 6080, 6279, 6320, 6510, 6655, 6636, 6870, 7145, 7195, 6999, 6971, 7296, 7211
Offset: 1

Views

Author

Ilya Gutkovskiy, Jan 30 2023

Keywords

Crossrefs

A360215 a(n) is the smallest positive integer which can be represented as the sum of distinct nonzero icosahedral numbers in exactly n ways, or -1 if no such integer exists.

Original entry on oeis.org

1, 1383, 4157, 6548, 8633, 9884, 12503, 12920, 15357, 15812, 18146, 18126, 19755, 20895, 22106, 23229, 23246, 23685, 22118, 25142, 25884, 27894, 29448, 28149, 29703, 30285, 31914, 30966, 34007, 34380, 34390, 35082, 35894, 34389, 36891, 37035, 37425, 35907, 35895, 38856
Offset: 1

Views

Author

Ilya Gutkovskiy, Jan 30 2023

Keywords

Crossrefs

A360216 a(n) is the smallest positive integer which can be represented as the sum of distinct nonzero dodecahedral numbers in exactly n ways, or -1 if no such integer exists.

Original entry on oeis.org

1, 2025, 2925, 9010, 15521, 18465, 19140, 24899, 32760, 33576, 36245, 39746, 39290, 39270, 46540, 50215, 49055, 53680, 50435, 56585, 58990, 57460, 58380, 61950, 63329, 64600, 63700, 64550, 67305, 68530, 71690
Offset: 1

Views

Author

Ilya Gutkovskiy, Jan 30 2023

Keywords

Crossrefs

A360217 a(n) is the smallest positive integer which can be represented as the sum of n distinct nonzero tetrahedral numbers in exactly n ways, or -1 if no such integer exists.

Original entry on oeis.org

1, 140, 305, 315, 435, 644, 830, 1141, 1425, 1925, 2380, 3010, 3805, 4720, 5806, 7095, 8510, 10200, 12020, 14115, 16460, 19131, 21990, 25425, 29275, 33495, 37425, 42680, 48300, 54545, 60711, 68391, 75726, 84815, 93370, 103250, 114115, 125360, 137831, 150995, 165545, 179830
Offset: 1

Views

Author

Ilya Gutkovskiy, Jan 30 2023

Keywords

Examples

			For n = 3: 305 = 1 + 84 + 220 = 20 + 120 + 165 = 56 + 84 + 165.
		

Crossrefs

Extensions

More terms from David A. Corneth, Jan 30 2023
Showing 1-7 of 7 results.