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, 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

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