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 A241928 a(n) = smallest k such that lambda(n+k) = lambda(k). 1
 1, 4, 3, 4, 3, 6, 7, 4, 3, 5, 5, 9, 13, 7, 5, 8, 17, 6, 9, 4, 3, 11, 23, 16, 5, 13, 9, 14, 7, 10, 31, 13, 9, 17, 5, 36, 37, 10, 13, 20, 41, 14, 5, 16, 15, 23, 9, 36, 7, 10, 17, 13, 52, 9, 5, 7, 13, 14, 45, 20, 61, 31, 9, 16, 7, 18, 45, 17, 23, 10, 71, 45, 39 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 COMMENTS Lambda(n) is the Carmichael lambda function(A002322). It is highly probable that a solution exists for each n>0. The corresponding values of lambda(k) are 1, 2, 2, 2, 2, 2, 6, 2, 2, 4, 4, 6, 12, 6, 4, 2, 16, 2, 6, 2, 2, 10, 22, 4, 4, 12, 6, 6, 6, 4, 30, ... LINKS Michel Lagneau, Table of n, a(n) for n = 1..10000 EXAMPLE a(29) = 7 because lambda(29+7) = lambda(7) = 6. MAPLE with(numtheory):for n from 1 to 70 do:ii:=0:for k from 1 to 10^8 while(ii=0) do:if lambda(k) = lambda(k+n) then ii:=1:printf(`%d, `, k):else fi:od:od: MATHEMATICA klambda[n_]:=Module[{k=1}, While[CarmichaelLambda[n+k]!= CarmichaelLambda [k], k++]; k]; Array[klambda, 70] CROSSREFS Cf. A002322, A007015, A173695. Sequence in context: A168309 A103947 A178038 * A111048 A016700 A088910 Adjacent sequences:  A241925 A241926 A241927 * A241929 A241930 A241931 KEYWORD nonn AUTHOR Michel Lagneau, May 02 2014 STATUS approved

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Last modified August 14 01:44 EDT 2020. Contains 336474 sequences. (Running on oeis4.)