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 A360942 a(n) is the least k such that k*n is a happy number (A007770). 2
 1, 5, 43, 7, 2, 32, 1, 4, 125, 1, 4, 16, 1, 2, 75, 2, 4, 64, 1, 5, 49, 2, 1, 8, 4, 5, 44, 1, 7, 43, 1, 1, 34, 2, 2, 32, 24, 5, 28, 7, 2, 26, 2, 1, 25, 5, 2, 4, 1, 2, 22, 4, 17, 22, 8, 5, 16, 8, 4, 32, 11, 5, 21, 3, 2, 17, 7, 1, 22, 1, 13, 16, 3, 12, 15, 8, 11 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 COMMENTS This sequence is well defined (see A360941). LINKS Rémy Sigrist, Table of n, a(n) for n = 1..10000 FORMULA a(n) = A360941(n) / n. a(n) = 1 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 / n))) } CROSSREFS Cf. A007770, A360941. Sequence in context: A368352 A132487 A178614 * A284170 A067927 A038546 Adjacent sequences: A360939 A360940 A360941 * A360943 A360944 A360945 KEYWORD nonn,base AUTHOR Rémy Sigrist, Feb 26 2023 STATUS approved

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Last modified August 9 04:00 EDT 2024. Contains 375027 sequences. (Running on oeis4.)