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 A233929 Smallest x such that sigma(x) == n-1 (mod n). 2
 1, 1, 7, 2, 3, 2401, 5, 4, 7, 18, 21, 9604, 6, 9, 13, 8, 44, 21609, 10, 18, 19, 289, 36, 9604, 14, 162, 57, 72, 12, 2614689, 29, 16, 21, 625, 63, 38416, 22, 4608, 37, 18, 27, 21609, 20, 289, 43, 36, 50, 38416, 33, 196, 111, 162, 157, 28561, 34, 1296, 28, 49 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,3 COMMENTS Right subdiagonal of A074625. Records values are: 1, 7, 2401, 9604, 21609, 2614689, 21215236, 36324729, 53304601, 338964921, 431642176, 528264256, 1307979556, ... obtained at indices: 1, 3, 6, 12, 18, 30, 60, 210, 288, 384, 534, 630, 732. - Michel Marcus, Dec 22 2013 LINKS Michel Marcus and Donovan Johnson, Table of n, a(n) for n = 1..3000 (first 800 terms from Michel Marcus) PROG (PARI) a(n) = {x = 1; while ((sigma(x) % n) != (n - 1), x++); x; } \\ Michel Marcus, Dec 18 2013 CROSSREFS Cf. A000203, A070982, A074625. Sequence in context: A193027 A248288 A248287 * A241427 A197761 A199269 Adjacent sequences:  A233926 A233927 A233928 * A233930 A233931 A233932 KEYWORD nonn AUTHOR Michel Marcus, Dec 18 2013 STATUS approved

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Last modified October 22 22:34 EDT 2019. Contains 328335 sequences. (Running on oeis4.)