A353463 Characteristic function of lesser twin primes: a(n) = 1 if both n and n+2 are primes, otherwise 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, 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

Links

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

Index entries for characteristic functions

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. A010051, A353464.

Cf. also A156659, A156660.

Sequence in context: A059125 A189820 A111406 * A260445 A156731 A254379

Adjacent sequences: A353460 A353461 A353462 * A353464 A353465 A353466

Keyword

nonn

Author

Antti Karttunen, Apr 22 2022

Status

approved