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Number of compositions (ordered partitions) of n into prime power parts (A246655) such that no two adjacent parts are equal (Carlitz compositions).
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%I #4 Mar 22 2018 17:57:02

%S 1,0,1,1,1,3,2,6,5,12,14,22,35,44,79,99,165,228,346,516,742,1140,1624,

%T 2479,3592,5370,7933,11684,17421,25557,38098,56053,83207,122958,

%U 181848,269426,397900,589749,871302,1290349,1908208,2823440,4178248,6179602,9146534,13527806,20019958

%N Number of compositions (ordered partitions) of n into prime power parts (A246655) such that no two adjacent parts are equal (Carlitz compositions).

%H <a href="/index/Com#comp">Index entries for sequences related to compositions</a>

%F G.f.: 1/(1 - Sum_{p prime, k>=1} x^(p^k)/(1 + x^(p^k))).

%e a(8) = 5 because we have [8], [5, 3], [3, 5], [3, 2, 3] and [2, 4, 2].

%t nmax = 46; CoefficientList[Series[1/(1 - Sum[Boole[PrimePowerQ[k]] x^k/(1 + x^k), {k, 1, nmax}]), {x, 0, nmax}], x]

%Y Cf. A003242, A246655, A280195, A301428, A301500.

%K nonn

%O 0,6

%A _Ilya Gutkovskiy_, Mar 22 2018