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A115239 a(1) = floor(Pi) = 3; a(n+1) = floor(a(n)*Pi). 4

%I #21 Apr 11 2021 04:08:29

%S 3,9,28,87,273,857,2692,8457,26568,83465,262213,823766,2587937,

%T 8130243,25541911,80242279,252088554,791959549,2488014301,7816327450,

%U 24555716894,77144059797,242355211526,761381352089,2391950062303

%N a(1) = floor(Pi) = 3; a(n+1) = floor(a(n)*Pi).

%C a(n+1)/a(n) converges to Pi. Similar to sequence A085839 but with a simpler definition.

%C Subset of the Beatty sequence of Pi = A022844 = floor(n*Pi). Primes in this sequence include a(1) = 3, a(6) = 857, a(15) = 25541911. - _Jonathan Vos Post_, Jan 18 2006

%H G. C. Greubel, <a href="/A115239/b115239.txt">Table of n, a(n) for n = 1..1000</a>

%H Eric Weisstein's World of Mathematics, <a href="http://mathworld.wolfram.com/BeattySequence.html">Beatty Sequence</a>.

%e a(2) = floor(a(1)*Pi) = floor(3*Pi) = 9;

%e a(3) = floor(a(2)*Pi) = floor(9*Pi) = 28;

%e a(4) = floor(a(3)*Pi) = floor(28*Pi) = 87.

%p A[1]:= 3:

%p for n from 2 to 50 do A[n]:= floor(Pi*A[n-1]) od:

%p seq(A[i],i=1..50); # _Robert Israel_, Feb 07 2016

%t a[1] = Floor[Pi]; a[n_] := a[n] = Floor[a[n - 1]*Pi]; Array[a, 25] (* _Robert G. Wilson v_, Jan 18 2006 *)

%t NestList[Floor[Pi #]&,3,30] (* _Harvey P. Dale_, Mar 30 2012 *)

%Y Cf. A085839.

%Y Cf. A022844, A038130, A054386, A108591.

%K nonn

%O 1,1

%A _Hieronymus Fischer_, Jan 17 2006

%E More terms from _Robert G. Wilson v_, Jan 18 2006

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Last modified April 16 01:01 EDT 2024. Contains 371696 sequences. (Running on oeis4.)