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A081730 Numbers n such that the n-th Euler number == 1 (mod n). 3

%I #13 Apr 18 2015 15:08:07

%S 1,2,3,4,5,7,8,11,13,15,16,17,19,23,29,31,32,37,41,43,47,53,59,61,64,

%T 67,71,73,79,83,89,91,97,101,103,107,109,113,127,128,131,137,139,149,

%U 151,157,163,167,173,179,181,191,193,197,199,211,223,227,229,233,239,241

%N Numbers n such that the n-th Euler number == 1 (mod n).

%F All primes, all power of 2 are in the sequence. The composites are in A035163.

%o (PARI) a000364(n)=subst(bernpol(2*n+1), 'x, 1/4)*4^(2*n+1)*(-1)^(n+1)/(2*n+1);

%o lista(nn) = {for (n=1, nn, if (Mod(a000364(n), n) == 1, print1(n, ", ")););} \\ _Michel Marcus_, Apr 18 2015

%Y Cf. A000364, A035163, A069042.

%K nonn

%O 1,2

%A _Benoit Cloitre_, Apr 06 2003

%E More terms from Weston Markham (weston.markham(AT)gmail.com), May 22 2005

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Last modified March 28 14:38 EDT 2024. Contains 371254 sequences. (Running on oeis4.)