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.

A307738 Number of partitions of n^3 into at most n cubes.

Original entry on oeis.org

1, 1, 1, 1, 1, 1, 3, 4, 7, 18, 36, 66, 157, 329, 728, 1611, 3655, 8062, 18154, 40358, 89807, 199778, 444419, 984422, 2183461, 4827756, 10651083, 23465459, 51576034, 113092423, 247546849, 540538832, 1177836149, 2560897979, 5555722749, 12025952101, 25976048200
Offset: 0

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Author

Ilya Gutkovskiy, Apr 25 2019

Keywords

Comments

Does a(n+1) / a(n) ~ 2? - David A. Corneth, Sep 27 2019

Examples

			7^3 =
1^3 + 1^3 + 5^3 + 6^3 =
1^3 + 1^3 + 3^3 + 4^3 + 5^3 + 5^3 =
1^3 + 2^3 + 3^3 + 3^3 + 4^3 + 6^3,
so a(7) = 4.
		

Crossrefs

Programs

  • PARI
    a(n) = {my(res = 0); res=aIterate(n^3, 1, n); res }
    aIterate(s, m, q) = { if(s == 0, return(1)); if(q == 0, return(0)); sum(i = m, sqrtnint(s, 3), aIterate(s - i^3, i, q-1) ) } \\ David A. Corneth, Sep 23 2019

Extensions

a(21)-a(36) from David A. Corneth, Sep 23 2019

A338586 Number of partitions of the n-th tetrahedral number into exactly n positive tetrahedral numbers.

Original entry on oeis.org

1, 1, 0, 0, 0, 1, 2, 5, 5, 20, 35, 75, 154, 336, 730, 1570, 3394, 7339, 16085, 35015, 76269, 164821, 359704, 782004, 1696804, 3668860, 7953962, 17184203, 37093184, 79825297, 171824175, 368838299, 790404448, 1690297309, 3610816466, 7696144659, 16374004711, 34766160358
Offset: 0

Views

Author

Ilya Gutkovskiy, Nov 08 2020

Keywords

Examples

			The 6th tetrahedral number is 56 and 56 = 1 + 1 + 4 + 10 + 20 + 20 = 4 + 4 + 4 + 4 + 20 + 20, so a(6) = 2.
		

Crossrefs

Formula

a(n) = [x^A000292(n) y^n] Product_{j>=1} 1 / (1 - y*x^A000292(j)).

A307644 Number of partitions of n^4 into exactly n nonzero fourth powers.

Original entry on oeis.org

1, 1, 0, 0, 0, 1, 1, 0, 0, 0, 1, 3, 0, 6, 0, 27, 13, 59, 390, 661, 4933, 9760, 49415, 101967, 341887, 702884, 2209559, 5361004, 15472531, 34165997, 82258594, 193682533, 490404772, 1210929426, 2725005202, 6283337761, 13672859806, 34906926846
Offset: 0

Views

Author

Ilya Gutkovskiy, Apr 19 2019

Keywords

Examples

			11^4 =
1^4 + 2^4 + 2^4 + 4^4 + 4^4 + 4^4 + 4^4 + 6^4 + 8^4 + 8^4 + 8^4 =
2^4 + 2^4 + 2^4 + 2^4 + 2^4 + 2^4 + 6^4 + 6^4 + 6^4 + 8^4 + 9^4 =
2^4 + 2^4 + 2^4 + 4^4 + 6^4 + 6^4 + 6^4 + 6^4 + 6^4 + 6^4 + 9^4,
so a(11) = 3.
		

Crossrefs

Extensions

a(20)-a(28) from Vaclav Kotesovec, Apr 20 2019
a(29)-a(37) from Vaclav Kotesovec, Apr 23 2019
Showing 1-3 of 3 results.