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A384840

Numbers k for which sigma(k - x) + sigma(k + x) = 7*k has at least one nonnegative solution.

1952, 1992, 2016, 2160, 2520, 2640, 3314, 3744, 3801, 4320, 4484, 4500, 4566, 4620, 4680, 4994, 5016, 5948, 6072, 6096, 6194, 6384, 6492, 6552, 6654, 6870, 7056, 7200, 7224, 7382, 7435, 7440, 7470, 7794, 7812, 7920, 7956, 8376, 8480, 8604, 8616, 8702, 8892, 9284, 9360, 9408

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OFFSET

1,1

LINKS

Michel Marcus, Table of n, a(n) for n = 1..1000

PROG

(PARI) isok(k) = for (x=0, k-1, if (sigma(k - x) + sigma(k + x) == 7*k, return(1)));

CROSSREFS

Cf. A000203 (sigma), A055153 (a subsequence).

Cf. A383268, A384838, A384839, A384841.

Cf. A383758.

Sequence in context: A223464 A252062 A251843 * A249202 A249324 A249217