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Jianing Song, <a href="/A319282/b319282.txt">Table of n, a(n) for n = 1..9999</a> (all terms <= 150000)

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Fourth powers: positvepositive: A319281; negative: this sequence (negated).

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Michel Marcus: typo

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15, 31, 47, 63, 79, 95, 111, 127, 143, 159, 175, 191, 207, 223, 239, 240, 241, 255, 271, 287, 303, 319, 335, 351, 367, 383, 399, 415, 431, 447, 463, 479, 495, 496, 511, 527, 543, 559, 575, 591, 607, 623, 639, 655, 671, 687, 703, 719, 735, 751, 752, 767, 783, 799, 815

a(n) = 15*n + O(log(n)).

(PARI) isA319282(n)= n\16^valuation(n, 16)%16==15

A125169 is a proper subsequence.

{-a(n)} aregives all negative fourth powers modulo all powers of 2, that is, negative fourth powers over 2-adic integers.

Perfect powers over 2-adic integers:

Squares: positive: A234000; negative: A004215 (negated);

Cubes: A191257;

Fourth powers: positve: A319281; negative: this sequence (negated).