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.

A345843 Numbers that are the sum of nine fourth powers in exactly one ways.

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%I A345843 #6 Jul 31 2021 21:28:12
%S A345843 9,24,39,54,69,84,89,99,104,114,119,129,134,144,149,164,169,179,184,
%T A345843 194,199,209,214,229,244,249,259,274,329,354,369,384,409,419,434,449,
%U A345843 484,489,499,514,569,594,609,624,633,648,649,659,663,674,678,689,693,708
%N A345843 Numbers that are the sum of nine fourth powers in exactly one ways.
%C A345843 Differs from A003343 at term 28 because 264 = 1^4 + 1^4 + 1^4 + 1^4 + 1^4 + 2^4 + 3^4 + 3^4 + 3^4 = 1^4 + 1^4 + 1^4 + 1^4 + 1^4 + 1^4 + 1^4 + 1^4 + 4^4.
%H A345843 Sean A. Irvine, <a href="/A345843/b345843.txt">Table of n, a(n) for n = 1..10000</a>
%e A345843 24 is a term because 24 = 1^4 + 1^4 + 1^4 + 1^4 + 1^4 + 1^4 + 1^4 + 1^4 + 2^4.
%o A345843 (Python)
%o A345843 from itertools import combinations_with_replacement as cwr
%o A345843 from collections import defaultdict
%o A345843 keep = defaultdict(lambda: 0)
%o A345843 power_terms = [x**4 for x in range(1, 1000)]
%o A345843 for pos in cwr(power_terms, 9):
%o A345843     tot = sum(pos)
%o A345843     keep[tot] += 1
%o A345843     rets = sorted([k for k, v in keep.items() if v == 1])
%o A345843     for x in range(len(rets)):
%o A345843         print(rets[x])
%Y A345843 Cf. A003343, A345793, A345833, A345844, A345853, A346336.
%K A345843 nonn
%O A345843 1,1
%A A345843 _David Consiglio, Jr._, Jun 26 2021