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

1,1

Comments

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

Links

Table of n, a(n) for n=1..66.

Prog

(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, ", ")))

Crossrefs

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

Sequence in context: A342378 A099047 A174392 * A333038 A049013 A267872

Adjacent sequences: A084923 A084924 A084925 * A084927 A084928 A084929

Keyword

nonn

Author

Paul D. Hanna, Jun 12 2003

Status

approved