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 A293246 a(n) is the smallest k > 1 such that A000166(k) is divisible by n!. 0
 2, 2, 3, 7, 25, 121, 241, 1681, 13441, 40321, 403201, 2016001, 3225601, 41932801, 609638401 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,1 COMMENTS a(n) is the smallest k > 1 such that round(k!/e) is divisible by n!. Terms are 0! + 1, 1! + 1, 2! + 1, 3! + 1, 4! + 1, 5! + 1, 6!/3 + 1, 7!/3 + 1, ... LINKS EXAMPLE a(3) = 7 because the smallest nonzero subfactorial number that is divisible by 3! is A000166(7) = 1854. MAPLE f:= proc(n) local k, t, p; p:= n!; t:= 0; for k from 2 do   t:= k*t + (-1)^k mod p;   if t = 0 then return k fi od: end proc: seq(f(n), n=0..13); # Robert Israel, Oct 03 2017 CROSSREFS Cf. A000142, A000166. Sequence in context: A083701 A076996 A139148 * A185387 A038507 A077001 Adjacent sequences:  A293243 A293244 A293245 * A293247 A293248 A293249 KEYWORD nonn,more AUTHOR Altug Alkan, Oct 03 2017 EXTENSIONS a(8)-a(14) from Robert Israel, Oct 03 2017 STATUS approved

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Last modified January 23 08:55 EST 2019. Contains 319376 sequences. (Running on oeis4.)