A263578 Positive values of k such that A014286(k) is divisible by k.

1, 3, 18, 24, 42, 48, 72, 96, 120, 138, 144, 192, 216, 240, 258, 264, 282, 288, 336, 360, 384, 402, 432, 480, 498, 576, 600, 618, 642, 648, 672, 714, 720, 744, 762, 768, 864, 912, 960, 978, 1002, 1008, 1080, 1104, 1152, 1200, 1224, 1296, 1320, 1338, 1344, 1362

Offset

1,2

Comments

Sequence is interesting because of the values of a(n) - a(n-1). For a(n) < 10000, the most common repeated values of a(n) - a(n-1) are 24 and 6. Will this situation continue?

Links

Table of n, a(n) for n=1..52.

Example

a(2) = 3 because Fibonacci(1) + 2 * Fibonacci(2) + 3 * Fibonacci(3) = 9, which is divisible by 3.

Mathematica

Select[Range@ 1584, Divisible[Sum[i Fibonacci@ i, {i, 0, #}], #] &] (* Michael De Vlieger, Oct 22 2015 *)

Prog

(PARI) for(n=1, 2000, if(sum(k=1, n, k*fibonacci(k)) % n == 0, print1(n, ", ")))

Crossrefs

Cf. A000045, A014286.

Sequence in context: A103715 A131860 A346421 * A048080 A306279 A169598

Adjacent sequences: A263575 A263576 A263577 * A263579 A263580 A263581

Keyword

nonn,easy

Author

Altug Alkan, Oct 22 2015

Status

approved