cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A119017 Primes from binary expansion of Pi, another version. Starting with the first bit of the binary expansion, A004601 = 1,1,0,0,1,0,0,1,0,0,0,0,1,1,1,1,1,1,0,1,1,0,1,... we move rightward until we encounter another 1. Since 11 (= 3 in decimal) is prime, we move to the next 1 and repeat the process.

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%I A119017 #11 Mar 07 2024 11:55:09
%S A119017 3,73,4639,67,3,3,3,3,3,5,3,5,5,5,17,17,1069,5,3,5,17,3,9099300883537,
%T A119017 17,3,5,19,3,17,19,3,17,3,19,3,17,5,17,5,3,3,257,3,5,3,3,131,3,3,19,3,
%U A119017 5,17,37,5,1153,1033,73,19,3,3,16657,17,17,5,19,3,19,3,3,3,3,19,3,17,3,3
%N A119017 Primes from binary expansion of Pi, another version. Starting with the first bit of the binary expansion, A004601 = 1,1,0,0,1,0,0,1,0,0,0,0,1,1,1,1,1,1,0,1,1,0,1,... we move rightward until we encounter another 1. Since 11 (= 3 in decimal) is prime, we move to the next 1 and repeat the process.
%C A119017 Records: 3, 73, 4649, 9099300883537, 37848784972821936516494858855515680431107854546647118951099098009925403829863969526043052181881, ..., . - _Robert G. Wilson v_, Jul 24 2006
%e A119017 11 = 3
%e A119017 1001001 = 73
%e A119017 1001000011111 = 4639
%e A119017 1000011 = 67
%e A119017 11 = 3
%e A119017 11 = 3
%e A119017 11 = 3
%t A119017 ps = First@RealDigits[Pi, 2, 10^3]; lst = {}; Do[k = 1; While[fd = FromDigits[ Take[ps, k], 2]; EvenQ@fd || ! PrimeQ@fd, k++ ]; AppendTo[lst, fd]; j = 1; While[ ps[[j]] != 1, j++ ]; ps = Drop[ps, j], {n, 77}]; lst (* _Robert G. Wilson v_, Jul 24 2006 *)
%Y A119017 Cf. A004601, A068425, A117721, A065987.
%K A119017 nonn,base
%O A119017 1,1
%A A119017 _Russell Walsmith_, Jul 23 2006
%E A119017 More terms from _Robert G. Wilson v_, Jul 24 2006