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A093521 Runs of 1's of lengths 1, prime(1), prime(2), prime(3), ... separated by 0's. 3
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, 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, 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 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Carl Sagan's "Contact" sequence.

Zeros occur at positions given by 1+A110895(k). - Antti Karttunen, Nov 08 2018

REFERENCES

W. A. Dembski and J. M. Kushiner, Signs of Intelligence, Baker Book House Co., Grand Rapids, MI, p30-31, 2001,

Carl Sagan, Contact, Simon and Schuster, Chapter 4 "Prime Numbers," pp. 68-82, NY, 1985.

LINKS

Antti Karttunen, Table of n, a(n) for n = 1..24235 (first 101 runs)

Robin Dougherty, Robert Zemeckis' Contact, Salon.

Alex Kasman, Mathematical Fiction, Contact (1985).

Alex Kasman, How 'Contact' by Carl Sagan Ends.

Index entries for characteristic functions

MATHEMATICA

a = Table[1, {100}]; Do[ a[[Sum[Prime[i], {i, n}] + n]] = 0, {n, 1, 8}]; a

PROG

(PARI)

up_to = 111;

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)); };

v093521 = A093521list(up_to);

A093521(n) = v093521[n];

CROSSREFS

Cf. A000040, A000042, A005171, A031974, A055976, A056051, A066247, A091247, A110895, A175851, A175856.

Sequence in context: A117567 A307183 A117568 * A187948 A188433 A267635

Adjacent sequences:  A093518 A093519 A093520 * A093522 A093523 A093524

KEYWORD

nonn

AUTHOR

Robert G. Wilson v, Mar 29 2004

EXTENSIONS

Data section extended up to n=111 by Antti Karttunen, Nov 08 2018

STATUS

approved

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Last modified September 27 00:14 EDT 2020. Contains 337378 sequences. (Running on oeis4.)