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 A084926 Inverse hyperbolic cotangent reducible numbers. The hyperbolic analog of the non-Stormer numbers (A002312). 2

%I

%S 5,7,9,11,13,15,17,19,21,23,25,26,27,29,31,33,34,35,37,39,41,43,45,47,

%T 49,51,53,55,56,57,59,61,63,64,65,67,69,71,73,75,76,77,79,81,83,85,86,

%U 87,89,91,93,94,95,97,99,101,103,105,107,109,111,113,115,116,117,118

%N Inverse hyperbolic cotangent reducible numbers. The hyperbolic analog of the non-Stormer numbers (A002312).

%C n is in the sequence if y=(xn+1)/(x+n) is an integer for some integer x where 1<x<n.

%o (PARI) for(n=1,120,x=1; b=0; while(x<n,x=x+1; r=(x+n)*floor((x*n+1)/(x+n)); if(r>=(x*n+1),b=b+1)); if(b>0,print1(n,",")))

%Y Cf. A002312 (non-Stormer numbers), A084925 (arccoth irreducible).

%K nonn

%O 1,1

%A _Paul D. Hanna_, Jun 12 2003

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Last modified September 25 16:13 EDT 2020. Contains 337344 sequences. (Running on oeis4.)