A080198 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, a(n+1)>a(n) and x=(5/4).

1, 2, 4, 6, 14, 34, 44, 49, 137, 142, 235, 333, 426, 519, 710, 994, 1278, 1562, 1846, 2130, 2414, 2698, 2982, 3266, 3550, 3834, 4118, 4402, 4686, 4970, 5254, 5538, 5822, 6106, 6390, 6674, 6958, 7242, 7526, 7810, 8094, 8378, 8662, 8946, 9230, 9514, 9798

Offset

1,2

Links

Table of n, a(n) for n=1..47.

Prog

(PARI) x=(5/4); z=cos(x)^2; a=1; for(n=1, 64, b=a+1; while(z+cos(b*x)^2>1, b++); z=z+cos(b*x)^2; a=b; print1(b, ", "))

Crossrefs

Cf. A080136, A080137, A080138, A080139, A080140.

Sequence in context: A251393 A058059 A053686 * A376809 A077637 A077639

Adjacent sequences: A080195 A080196 A080197 * A080199 A080200 A080201

Keyword

nonn

Author

Paul D. Hanna, Feb 04 2003

Status

approved