A364662 Numbers k such that sigma(k) < sigma(k+1) < sigma(k+2) < sigma(k+3).

1, 61, 73, 133, 145, 193, 253, 397, 457, 481, 493, 553, 565, 613, 625, 661, 673, 733, 757, 793, 817, 853, 913, 973, 997, 1033, 1093, 1213, 1237, 1285, 1321, 1453, 1513, 1537, 1645, 1657, 1681, 1813, 1825, 1873, 1933, 2077, 2113, 2173, 2233, 2245, 2293, 2413, 2497, 2533, 2581, 2593, 2653, 2713

Offset: 1

Author

Seiichi Manyama, Aug 01 2023

Keywords

• nonn
• easy

Links

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

Crossrefs

Cf. A050944, A053224, A364659.

Programs

PARI

isok(n) = sigma(n)