A070290 a(n) = lcm(8,n)/gcd(8,n).

8, 4, 24, 2, 40, 12, 56, 1, 72, 20, 88, 6, 104, 28, 120, 2, 136, 36, 152, 10, 168, 44, 184, 3, 200, 52, 216, 14, 232, 60, 248, 4, 264, 68, 280, 18, 296, 76, 312, 5, 328, 84, 344, 22, 360, 92, 376, 6, 392, 100, 408, 26, 424, 108, 440, 7, 456, 116, 472, 30, 488

Offset: 1

Author

Amarnath Murthy, May 10 2002

Keywords

• easy
• nonn

Links

• Index entries for linear recurrences with constant coefficients, signature (0,0,0,0,0,0,0,2,0,0,0,0,0,0,0,-1)

Crossrefs

Cf. A070291, A070292, A070293, A109011, A109049.

Programs

Mathematica

LinearRecurrence[{0,0,0,0,0,0,0,2,0,0,0,0,0,0,0,-1}, {8,4,24,2,40,12,56,1,72,20,88,6,104,28,120,2}, 37] (* Georg Fischer, Feb 27 2019 *)

Formula

a(n) = A109049(n) / A109011(n). - R. J. Mathar, Feb 12 2019

a(n) = 2*a(n-8)-a(n-16). - R. J. Mathar, Feb 12 2019

Sum_{k=1..n} a(k) ~ (293/128)*n^2. - Amiram Eldar, Oct 07 2023