A345856 Numbers that are the sum of ten fourth powers in exactly four ways.
1620, 2660, 2725, 2740, 2835, 2855, 2870, 2900, 2915, 2920, 2950, 2965, 2980, 3000, 3015, 3030, 3045, 3095, 3160, 3220, 3240, 3255, 3285, 3335, 3350, 3415, 3430, 3460, 3479, 3510, 3525, 3544, 3559, 3574, 3589, 3639, 3654, 3685, 3700, 3719, 3765, 3784, 3799
Offset: 1
Keywords
Examples
2660 is a term because 2660 = 1^4 + 1^4 + 1^4 + 1^4 + 2^4 + 2^4 + 2^4 + 2^4 + 6^4 + 6^4 = 1^4 + 1^4 + 1^4 + 3^4 + 4^4 + 4^4 + 4^4 + 4^4 + 4^4 + 6^4 = 1^4 + 2^4 + 2^4 + 2^4 + 2^4 + 2^4 + 2^4 + 3^4 + 3^4 + 7^4 = 2^4 + 3^4 + 3^4 + 3^4 + 3^4 + 4^4 + 4^4 + 4^4 + 4^4 + 6^4.
Links
- Sean A. Irvine, Table of n, a(n) for n = 1..10000
Programs
-
Python
from itertools import combinations_with_replacement as cwr from collections import defaultdict keep = defaultdict(lambda: 0) power_terms = [x**4 for x in range(1, 1000)] for pos in cwr(power_terms, 10): tot = sum(pos) keep[tot] += 1 rets = sorted([k for k, v in keep.items() if v == 4]) for x in range(len(rets)): print(rets[x])
Comments