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 A200982 Numbers k such that 1^(lambda(k)/2) + 2^(lambda(k)/2) + ... + (k - 1)^(lambda(k)/2) = 0 (mod k), where lambda is the Carmichael reduced totient function. 1
 1, 3, 5, 7, 9, 11, 13, 17, 19, 21, 23, 25, 27, 28, 29, 31, 33, 36, 37, 41, 43, 44, 47, 49, 53, 56, 57, 59, 61, 63, 65, 67, 69, 71, 72, 73, 76, 77, 79, 81, 83, 84, 88, 89, 92, 93, 97, 99, 101, 103, 107, 108, 109, 113, 121, 124, 125, 127, 129, 131, 132, 133 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 COMMENTS Conjecture: The asymptotic density is zero. LINKS Amiram Eldar, Table of n, a(n) for n = 1..10000 MATHEMATICA Select[Range[200], (Mod[Sum[PowerMod[j, CarmichaelLambda[#]/2, #], {j, #}], #] == 0) &] CROSSREFS Cf. A002322 (the reduced totient function). Sequence in context: A184591 A033040 A335241 * A084820 A324846 A324760 Adjacent sequences: A200979 A200980 A200981 * A200983 A200984 A200985 KEYWORD nonn AUTHOR José María Grau Ribas, Nov 25 2011 STATUS approved

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Last modified July 13 07:46 EDT 2024. Contains 374274 sequences. (Running on oeis4.)