cp's OEIS Frontend

A093521 Runs of 1's of lengths 1, prime(1), prime(2), prime(3), ... separated by 0's.

%I A093521 #17 Nov 08 2018 21:12:29
%S A093521 1,0,1,1,0,1,1,1,0,1,1,1,1,1,0,1,1,1,1,1,1,1,0,1,1,1,1,1,1,1,1,1,1,1,
%T A093521 0,1,1,1,1,1,1,1,1,1,1,1,1,1,0,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,0,1,
%U A093521 1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,0,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,0
%N A093521 Runs of 1's of lengths 1, prime(1), prime(2), prime(3), ... separated by 0's.
%C A093521 Carl Sagan's "Contact" sequence.
%C A093521 Zeros occur at positions given by 1+A110895(k). - _Antti Karttunen_, Nov 08 2018
%D A093521 W. A. Dembski and J. M. Kushiner, Signs of Intelligence, Baker Book House Co., Grand Rapids, MI, p30-31, 2001,
%D A093521 Carl Sagan, Contact, Simon and Schuster, Chapter 4 "Prime Numbers," pp. 68-82, NY, 1985.
%H A093521 Antti Karttunen, <a href="/A093521/b093521.txt">Table of n, a(n) for n = 1..24235 (first 101 runs)</a>
%H A093521 Robin Dougherty, <a href="http://www.salon.com/1997/08/11/contact_2/">Robert Zemeckis' Contact</a>, Salon.
%H A093521 Alex Kasman, <a href="http://kasmana.people.cofc.edu/MATHFICT/mfview.php?callnumber=mf55">Mathematical Fiction, Contact (1985)</a>.
%H A093521 Alex Kasman, <a href="http://kasmana.people.cofc.edu/MATHFICT/mf55-spoiler.html">How 'Contact' by Carl Sagan Ends</a>.
%H A093521 <a href="/index/Ch#char_fns">Index entries for characteristic functions</a>
%t A093521 a = Table[1, {100}]; Do[ a[[Sum[Prime[i], {i, n}] + n]] = 0, {n, 1, 8}]; a
%o A093521 (PARI)
%o A093521 up_to = 111;
%o A093521 A093521list(up_to) = { my(v=vector(up_to), i=2, j); v[1] = 1; v[2] = 0; forprime(p=2, oo, j=p; while(j, if(i==up_to, return(v), i++; v[i] = 1; j--)); if(i==up_to, return(v), i++; v[i] = 0)); };
%o A093521 v093521 = A093521list(up_to);
%o A093521 A093521(n) = v093521[n];
%Y A093521 Cf. A000040, A000042, A005171, A031974, A055976, A056051, A066247, A091247, A110895, A175851, A175856.
%K A093521 nonn
%O A093521 1,1
%A A093521 _Robert G. Wilson v_, Mar 29 2004
%E A093521 Data section extended up to n=111 by _Antti Karttunen_, Nov 08 2018