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Expansion of Pi^2 in golden base (i.e., in irrational base phi = (1 + sqrt(5))/2).
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%I #14 Aug 07 2020 12:11:47

%S 1,0,1,0,0,0,1,0,0,0,0,0,0,1,0,0,0,1,0,0,0,1,0,1,0,0,1,0,1,0,1,0,1,0,

%T 0,1,0,0,1,0,1,0,1,0,0,1,0,0,0,0,1,0,1,0,0,0,1,0,0,0,1,0,0,1,0,0,0,0,

%U 1,0,1,0,0,0,1,0,0,0,1,0,0,1,0,0,0,0,0,0,0,1,0,1,0,0,1,0,1,0,1,0,0,1,0,0,0

%N Expansion of Pi^2 in golden base (i.e., in irrational base phi = (1 + sqrt(5))/2).

%H J. Borwein and M. Chamberland, <a href="https://archive.siam.org/journals/categories/06-003.php">A golden example</a>.

%H D. H. Bailey, <a href="https://www.davidhbailey.com/dhbpapers/bbp-formulas.pdf">A compendium of BBP-type formulas for mathematical constants</a>.

%H E. Weisstein, <a href="http://mathworld.wolfram.com/BBP-TypeFormula.html">BBP type formula (formula 16)</a>.

%e Pi^2 = 10100.01000000100010001010010101010010... in golden base

%t RealDigits[Pi^2,GoldenRatio,120][[1]] (* _Harvey P. Dale_, Sep 19 2016 *)

%o (PARI) f=(1+sqrt(5))/2;z=Pi^2;b=0;m=100;for(n=1,m,c=ceil(log(z)/log(1/f));z=z-1/f^c;b=b+1./10^c;if(n==m,print1(b,",")))

%K base,cons,nonn

%O 0,1

%A _Benoit Cloitre_, Feb 18 2005