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 A344193 Numbers that are the sum of four fourth powers in exactly two ways 8
 259, 2674, 2689, 2754, 2929, 3298, 3969, 4144, 4209, 5074, 6579, 6594, 6659, 6769, 6834, 7203, 7874, 8194, 8979, 9154, 9234, 10113, 10674, 11298, 12673, 12913, 13139, 14674, 14689, 14754, 16563, 16643, 16818, 17187, 17234, 17299, 17314, 17858, 18963, 19699, 20658, 20739, 20979, 21154, 21219, 21329, 21363 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS Differs from A309763 at term 32 because 16578 = 1^4 + 2^4 + 9^4 + 10^4 = 2^4 + 5^4 + 6^4 + 11^4 = 3^4 + 7^4 + 8^4 + 10^4 LINKS David Consiglio, Jr., Table of n, a(n) for n = 1..20000 EXAMPLE 2689 is a member of this sequence because 2689 = 2^4 + 2^4 + 4^4 + 7^4 = 2^4 + 3^4 + 6^4 + 6^4 PROG (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, 50)] for pos in cwr(power_terms, 4): tot = sum(pos) keep[tot] += 1 rets = sorted([k for k, v in keep.items() if v == 2]) for x in range(len(rets)): print(rets[x]) CROSSREFS Cf. A025404, A309763, A344189, A344192, A344237, A344242, A344645. Sequence in context: A043376 A038480 A309763 * A254642 A322882 A256594 Adjacent sequences: A344190 A344191 A344192 * A344194 A344195 A344196 KEYWORD nonn AUTHOR David Consiglio, Jr., May 11 2021 STATUS approved

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Last modified September 25 13:12 EDT 2023. Contains 365647 sequences. (Running on oeis4.)