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.

A345146 Numbers that are the sum of four third powers in nine or more ways.

Original entry on oeis.org

21896, 36225, 42120, 46683, 46872, 48321, 48825, 50806, 50904, 51408, 51480, 51506, 51688, 52208, 52416, 53200, 53865, 54971, 55575, 56385, 57113, 58338, 58968, 59059, 60480, 60515, 60984, 62244, 62433, 65303, 66024, 66276, 66339, 66430, 67158, 67536, 67851
Offset: 1

Views

Author

David Consiglio, Jr., Jun 09 2021

Keywords

Examples

			42120 is a term because 42120 = 1^3 + 19^3 + 22^3 + 27^3  = 2^3 + 3^3 + 13^3 + 33^3  = 2^3 + 6^3 + 17^3 + 32^3  = 3^3 + 3^3 + 20^3 + 31^3  = 3^3 + 17^3 + 20^3 + 29^3  = 3^3 + 13^3 + 14^3 + 32^3  = 6^3 + 15^3 + 16^3 + 31^3  = 7^3 + 17^3 + 23^3 + 27^3  = 11^3 + 13^3 + 21^3 + 29^3.
		

Crossrefs

Programs

  • Python
    from itertools import combinations_with_replacement as cwr
    from collections import defaultdict
    keep = defaultdict(lambda: 0)
    power_terms = [x**3 for x in range(1, 1000)]
    for pos in cwr(power_terms, 4):
        tot = sum(pos)
        keep[tot] += 1
    rets = sorted([k for k, v in keep.items() if v >= 9])
    for x in range(len(rets)):
        print(rets[x])