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A252055 Number of products A000201(i)*A001950(j) = n. 1

%I #26 Dec 24 2014 00:27:28

%S 0,1,0,0,1,1,1,1,0,1,0,1,1,0,2,1,0,2,0,2,1,1,1,1,0,1,0,3,0,2,1,1,0,2,

%T 0,1,0,1,2,2,1,2,0,2,2,0,1,1,1,1,0,2,0,3,1,1,1,1,0,6,0,1,1,1,1,1,0,1,

%U 1,3,0,1,1,1,1,1,1,3,0,4,1,0,1,3,1,2

%N Number of products A000201(i)*A001950(j) = n.

%C A000201 and A001950 are the lower and upper Wythoff sequences, which partition the nonnegative integers.

%C Does this sequence include every nonnegative integer? What is the maximal number of consecutive 0's? What is the maximal number of consecutive 1's?

%H Clark Kimberling, <a href="/A252055/b252055.txt">Table of n, a(n) for n = 1..1000</a>

%e a(312) counts these 7 products: 3*104, 4*78, 6*52, 8*39, 12*26, 24*13, 156*2

%p N:= 1000: # to get a(1) to a(N)

%p A201:= [seq(floor(n*phi),n=1..N)]:

%p A1950:= [seq(floor(n*phi^2),n=1..N)]:

%p A:= Vector(N):

%p for i from 1 to N do

%p for j from 1 do

%p m:= A201[i]*A1950[j];

%p if m > N then break fi;

%p A[m]:= A[m]+1;

%p od

%p od:

%p convert(A,list); # _Robert Israel_, Dec 23 2014

%t r = (1 + Sqrt[5])/2; s = r/(r - 1); t = Flatten[Table[Floor[r*j]*Floor[s*k], {j, 1, 300}, {k, 1, 300}]]; a[n_] := Count[t, n]; u = Table[a[n], {n, 1, 300}]

%Y Cf. A000201, A001950.

%K nonn,easy

%O 1,15

%A _Clark Kimberling_, Dec 23 2014

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Last modified April 25 12:15 EDT 2024. Contains 371969 sequences. (Running on oeis4.)