A171387 - OEIS

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A171387

The characteristic function of primes > 3: 1 if n is prime such that neither prime+-1 is prime else 0.

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

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OFFSET

1,1

LINKS

Antti Karttunen, Table of n, a(n) for n = 1..1001

Index entries for characteristic functions

FORMULA

A010051(n) = a(n) + A171386(n).

If n > 3, a(n) = A010051(n), otherwise a(n) = 0. - Antti Karttunen, Oct 04 2017

CROSSREFS

Cf. A000007, A010051, A063524, A080545, A169546, A171386.

Sequence in context: A080679 A353464 A144193 * A355450 A333189 A011662

Adjacent sequences: A171384 A171385 A171386 * A171388 A171389 A171390

KEYWORD

nonn

AUTHOR

Juri-Stepan Gerasimov, Dec 07 2009

STATUS

approved