A360941 a(n) is the least multiple of m that is a happy number (A007770).

1, 10, 129, 28, 10, 192, 7, 32, 1125, 10, 44, 192, 13, 28, 1125, 32, 68, 1152, 19, 100, 1029, 44, 23, 192, 100, 130, 1188, 28, 203, 1290, 31, 32, 1122, 68, 70, 1152, 888, 190, 1092, 280, 82, 1092, 86, 44, 1125, 230, 94, 192, 49, 100, 1122, 208, 901, 1188, 440

Offset

1,2

Comments

This sequence is well defined as A007770 contains arbitrarily long subsequences of consecutive terms.

Links

Rémy Sigrist, Table of n, a(n) for n = 1..10000

Formula

a(n) = A360942(n) * n.

a(n) = n iff n belongs to A007770.

Prog

(PARI) a(n) = { forstep (m = n, oo, n, my (h = m, d); while (h > 6, d = digits(h); h = sum(k = 1, #d, d[k]^2)); if (h == 1, return (m))) }

Crossrefs

Cf. A007770, A360942.

Sequence in context: A296379 A183538 A184678 * A007819 A054050 A067313

Adjacent sequences: A360938 A360939 A360940 * A360942 A360943 A360944

Keyword

nonn,base

Author

Rémy Sigrist, Feb 26 2023

Status

approved