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A098972 a(0) = 1; for n > 0, a(n) = 2*a(floor(n/2)) + 3*a(floor(n/3)). 1

%I #13 Jul 13 2023 02:03:01

%S 1,5,13,25,41,41,89,89,121,157,157,157,301,301,301,301,365,365,581,

%T 581,581,581,581,581,965,965,965,1073,1073,1073,1073,1073,1201,1201,

%U 1201,1201,2065,2065,2065,2065,2065,2065,2065,2065,2065,2065,2065,2065,3025

%N a(0) = 1; for n > 0, a(n) = 2*a(floor(n/2)) + 3*a(floor(n/3)).

%C a(n) > a(n-1) iff n is a 3-smooth number.

%H Amiram Eldar, <a href="/A098972/b098972.txt">Table of n, a(n) for n = 0..10000</a>

%F sign(a(n+1)-a(n)) = A065333(n+1).

%t a[0] = 1; a[n_] := a[n] = 2*a[Floor[n/2]] + 3*a[Floor[n/3]]; Array[a, 50, 0] (* _Amiram Eldar_, Jul 13 2023 *)

%o (PARI) a(n)=if(n<1,1,a(floor(n/2))*2+3*a(floor(n/3)))

%Y Cf. A003586, A007731, A065333.

%K nonn

%O 0,2

%A _Benoit Cloitre_, Oct 23 2004

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Last modified March 29 10:59 EDT 2024. Contains 371277 sequences. (Running on oeis4.)