A087032 - OEIS

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A087032

a(n) = 1 if 2*A151800(n) - n is prime, otherwise 0, where A151800(n) is the smallest prime > n.

1, 0, 1, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 1, 0, 1, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 1, 0, 1, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 1, 0, 0, 0, 0, 0, 1, 0

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OFFSET

1,1

COMMENTS

There is no subsequence of two ones; number of zeros in each group is odd, see A087033.

LINKS

Antti Karttunen, Table of n, a(n) for n = 1..100000

Index entries for characteristic functions

FORMULA

a(n) = 1 if A087030(n) is prime, 0 if it is composite.

a(n) = A010051((2*A151800(n))-n). - Antti Karttunen, Oct 09 2018

EXAMPLE