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

5, 7, 9, 11, 13, 15, 17, 19, 21, 23, 25, 26, 27, 29, 31, 33, 34, 35, 37, 39, 41, 43, 45, 47, 49, 51, 53, 55, 56, 57, 59, 61, 63, 64, 65, 67, 69, 71, 73, 75, 76, 77, 79, 81, 83, 85, 86, 87, 89, 91, 93, 94, 95, 97, 99, 101, 103, 105, 107, 109, 111, 113, 115, 116, 117, 118

Offset: 1

Author

Paul D. Hanna, Jun 12 2003

Keywords

• nonn

Comments

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

Crossrefs

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

Programs

PARI

for(n=1,120,x=1; b=0; while(x=(x*n+1),b=b+1)); if(b>0,print1(n,",")))

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