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URL: https://oeis.org/A384838

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A384838
Numbers k for which sigma(k - x) + sigma(k + x) = 5*k has at least one nonnegative solution.
5
24, 53, 56, 63, 66, 74, 75, 79, 82, 84, 95, 112, 168, 192, 216, 227, 245, 252, 255, 274, 280, 282, 288, 308, 312, 347, 348, 351, 360, 365, 392, 395, 408, 420, 431, 432, 434, 458, 465, 466, 471, 476, 496, 528, 532, 560, 576, 579, 588, 624, 628, 644, 670, 694, 716, 720, 784
OFFSET
1,1
LINKS
PROG
(PARI) isok(k) = for (x=0, k-1, if (sigma(k - x) + sigma(k + x) == 5*k, return(1)));
CROSSREFS
Cf. A000203 (sigma), A141643 (a subsequence).
Cf. A383758.
Sequence in context: A070197 A190524 A211569 * A084586 A259023 A301575
KEYWORD
nonn
AUTHOR
Michel Marcus, Jun 10 2025
STATUS
approved