A364659 Numbers k such that sigma(k) < sigma(k+1) < sigma(k+2).

1, 2, 61, 62, 73, 74, 133, 134, 145, 146, 193, 194, 253, 254, 313, 397, 398, 403, 457, 458, 481, 482, 493, 494, 523, 553, 554, 565, 566, 613, 614, 625, 626, 661, 662, 673, 674, 691, 733, 734, 757, 758, 763, 793, 794, 817, 818, 853, 854, 913, 914, 943, 973, 974, 997, 998

Offset

1,2

Links

Seiichi Manyama, Table of n, a(n) for n = 1..10000

Prog

(PARI) isok(n) = sigma(n)<sigma(n+1) && sigma(n+1)<sigma(n+2);

Crossrefs

Cf. A053224, A364657, A364662.

Sequence in context: A101896 A130411 A262079 * A222009 A351728 A336297

Adjacent sequences: A364656 A364657 A364658 * A364660 A364661 A364662

Keyword

nonn,easy

Author

Seiichi Manyama, Aug 01 2023

Status

approved