A147953 -id:A147953 - cp's OEIS frontend

A147952 a(0) = 0, a(1) = a(2) = 1, and for n >= 3, a(n) = a(a(n-2)) + r(n), where r(n) = a(a(floor(n/3))) when n == 0 or 1 (mod 3) and = a(n - a(floor(n/3))) when n == 2 (mod 3).

0, 1, 1, 2, 2, 3, 2, 3, 4, 3, 3, 5, 3, 4, 5, 4, 5, 7, 4, 4, 6, 4, 4, 8, 4, 6, 6, 4, 4, 8, 4, 6, 10, 5, 6, 7, 4, 5, 9, 5, 5, 8, 6, 7, 7, 5, 5, 10, 6, 6, 7, 5, 6, 8, 4, 6, 8, 4, 6, 8, 4, 6, 10, 4, 5, 8, 5, 6, 8, 6, 8, 6, 6, 4, 10, 4, 5, 8, 5, 6, 13, 4, 6, 8, 4, 6, 8, 6, 8, 6, 6, 4, 10, 4, 5, 8, 6, 7, 10, 6, 6

Offset: 0

Roger L. Bagula, Nov 17 2008

nonn

Cf. A147665, A147953, A147981.

f[0] = 0; f[1] = 1; f[2] = 1; f[n_] := f[n] = f[f[n - 2]] + If[Mod[n, 3] == 0,f[f[n/3]], If[Mod[n, 3] == 1, f[f[(n - 1)/3]], f[n - f[(n - 2)/3]]]]; Table[f[n], {n, 0, 100}]

a(n) = a(a(n - 2)) + If[Mod[n, 3] == 0, a(a(n/3)), If[Mod[n, 3] == 1, a(a((n - 1)/3)), a(n - a((n - 2)/3))] for n >= 3 with a(0) = 0 and a(1) = a(2) = 1. [edited by Petros Hadjicostas, Apr 13 2020]

Name edited by Petros Hadjicostas, Apr 13 2020

A152006 Expansion of Product_{k > 0} (1 + f(k)*x^k), where f(1) = 1 and f(m) = prime(m-1) for m >= 2.

Original entry on oeis.org

1, 1, 2, 5, 8, 18, 34, 63, 102, 203, 336, 589, 999, 1675, 2799, 4768, 7561, 12224, 20513, 31724, 51621, 81976, 128560, 199192, 312536, 482806, 744847, 1147952, 1755931, 2649474, 4051413, 6069450, 9105323, 13747364, 20335077, 30508629, 45198631

Offset: 0

Roger L. Bagula, Nov 19 2008

nonn

Cf. A147557, A147654, A147655, A147665, A147869, A147871, A147880, A147953.

f[n_] = If[n < 2, n, Prime[n - 1]];
P[x_, n_] := P[x, n] = Product[1 + f[m]*x^m, {m, 0, n}];
Take[CoefficientList[P[x, 37], x],37]
(* Program edited and corrected by Petros Hadjicostas, Apr 12 2020 *)

a(n) = [x^n] Product_{k > 0} (1 + f(k)*x^k), where f(1) = 1 and f(m) = prime(m-1) for m >= 2.

Various sections edited by Petros Hadjicostas, Apr 12 2020

cp's OEIS Frontend

A147952 a(0) = 0, a(1) = a(2) = 1, and for n >= 3, a(n) = a(a(n-2)) + r(n), where r(n) = a(a(floor(n/3))) when n == 0 or 1 (mod 3) and = a(n - a(floor(n/3))) when n == 2 (mod 3).

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