A373054 Numbers k that divide the k-th tetranacci number (A000078).

1, 2, 22, 32, 80, 137, 179, 272, 320, 352, 600, 653, 859, 936, 991, 1279, 1280, 1306, 1601, 1609, 1632, 1672, 1982, 2089, 2152, 2437, 2560, 2591, 2693, 2789, 2897, 3120, 3202, 3701, 3823, 3847, 4110, 4212, 4451, 4691, 4751, 4919, 5120, 5182, 5280, 5386, 5431, 5479

Offset

1,2

Comments

Numbers k such that k | A000078(k).

Links

Amiram Eldar, Table of n, a(n) for n = 1..10000

Example

22 is a term since A000078(22) = 147312 = 22 * 6696 is divisible by 22.

Mathematica

With[{m = 10000}, Position[LinearRecurrence[{1, 1, 1, 1}, {0, 0, 1, 1}, m]/Range[m], _?IntegerQ] // Flatten]

Prog

(PARI) lista(kmax) = {my(t0 = 0, t1 = 0, t2 = 0, t3 = 1, t4 = 0); print1(1, ", ",  2, ", "); for(k = 4, kmax, t4 = t0 + t1 + t2 + t3; if(!(t4%k), print1(k, ", ")); t0 = t1; t1 = t2; t2 = t3; t3 = t4); }

Crossrefs

Cf. A000078.

Similar sequences: A014847 (Catalan), A016089 (Lucas), A023172 (Fibonacci), A051177 (partition), A232570 (tribonacci), A246692 (Pell), A266969 (Motzkin).

Sequence in context: A275029 A085185 A166726 * A156441 A094625 A130751

Adjacent sequences: A373051 A373052 A373053 * A373055 A373056 A373057

Keyword

nonn

Author

Amiram Eldar, May 20 2024

Status

approved