Voozh

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

(list; graph; refs; listen; history; text; internal format)

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