A080136 Least positive integer multiples of angle x such that their direction cosines form a unit vector: sum(k>0, cos(a(k)*x)^2)=1, where a(1)=1 and x=1.

1, 2, 4, 5, 8, 11, 33, 55, 77, 99, 121, 322, 344, 366, 388, 699, 39394, 49689, 51109, 51819, 52174, 52529, 156167, 156522, 260515, 364508, 364863, 573204, 885893, 1406923, 1719612, 4846147, 5992555, 10265498, 11411906, 15684849, 21104200

Offset

1,2

Links

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

Prog

(PARI) x=1; z=cos(x)^2; a=1; for(n=1, 45, b=a+1; while(z+cos(b*x)^2>1, b++); z=z+cos(b*x)^2; a=b; print1(b, ", "))

Crossrefs

Cf. A080137, A080138, A080139, A080140.

Sequence in context: A240179 A295032 A280017 * A080033 A007379 A080588

Adjacent sequences: A080133 A080134 A080135 * A080137 A080138 A080139

Keyword

nonn

Author

Paul D. Hanna, Jan 30 2003

Extensions

Extended with PARI program by Benoit Cloitre, Feb 04 2003

Status

approved