A384838 Numbers k for which sigma(k - x) + sigma(k + x) = 5*k has at least one nonnegative solution.

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

Michel Marcus, Table of n, a(n) for n = 1..5000

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. A383268, A384839, A384840, A384841.

Cf. A383758.

Sequence in context: A070197 A190524 A211569 * A084586 A259023 A301575

Adjacent sequences: A384835 A384836 A384837 * A384839 A384840 A384841

Keyword

nonn

Author

Michel Marcus, Jun 10 2025

Status

approved