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A364251 a(n) = 1 if n is of the form q*(2^k), where q is one of the Mersenne primes (A000668) and k >= 0, otherwise a(n) = 0. 4
0, 0, 1, 0, 0, 1, 1, 0, 0, 0, 0, 1, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 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, 0, 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, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 1, 0 (list; graph; refs; listen; history; text; internal format)
OFFSET
1
LINKS
Antti Karttunen, Table of n, a(n) for n = 1..65537
Index entries for characteristic functions
FORMULA
a(n) = [A331410(n) == 1], where [ ] is the Iverson bracket.
a(n) = [A364260(n) == 1].
a(n) <= A336923(n) <= A364252(n).
PROG
(PARI)
isA000668(n) = (isprime(n)&&!bitand(n, 1+n));
A364251(n) = isA000668(n>>valuation(n, 2));
CROSSREFS
Characteristic function of A335431.
Cf. A000668, A331410, A364260.
Cf. also A336923, A364252.
Sequence in context: A028999 A091244 A189632 * A365421 A131378 A354029
Adjacent sequences: A364248 A364249 A364250 * A364252 A364253 A364254
KEYWORD
nonn
AUTHOR
Antti Karttunen, Jul 16 2023
STATUS
approved

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Last modified August 31 00:13 EDT 2024. Contains 375550 sequences. (Running on oeis4.)