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A353463
Characteristic function of lesser twin primes: a(n) = 1 if both n and n+2 are primes, otherwise 0.
2
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, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 1, 0, 0, 0
OFFSET
1
FORMULA
a(n) = A010051(n) * A010051(n+2) = A353464(n+2).
PROG
(PARI) A353463(n) = (isprime(n) && isprime(n+2));
CROSSREFS
Characteristic function of A001359.
Cf. also A156659, A156660.
Sequence in context: A059125 A189820 A111406 * A260445 A156731 A254379
KEYWORD
nonn
AUTHOR
Antti Karttunen, Apr 22 2022
STATUS
approved