cp's OEIS Frontend

A373338 Characteristic function of A333242: a(n) = 1 if n is a term of A333242.

%I A373338 #40 Jul 02 2024 14:43:53
%S A373338 0,1,0,0,1,0,1,0,0,0,0,0,1,0,0,0,0,0,1,0,0,0,1,0,0,0,0,0,1,0,1,0,0,0,
%T A373338 0,0,1,0,0,0,0,0,1,0,0,0,1,0,0,0,0,0,1,0,0,0,0,0,1,0,1,0,0,0,0,0,0,0,
%U A373338 0,0,1,0,1,0,0,0,0,0,1,0,0,0,0,0,0,0,0,0,1,0,0,0,0,0,0,0,1,0,0,0
%N A373338 Characteristic function of A333242: a(n) = 1 if n is a term of A333242.
%C A373338 This sequence is the result of applying the N-sieve to generate the prime number subsequence A333242 where 1 indicates a prime number chosen to be included in sequence A333242 and 0 indicates the prime numbers and composites not in A333242.
%H A373338 Antti Karttunen, <a href="/A373338/b373338.txt">Table of n, a(n) for n = 1..100000</a>
%H A373338 Michael P. May, <a href="https://doi.org/10.35834/2020/3202158">Properties of Higher-Order Prime Number Sequences</a>, Missouri J. Math. Sci. (2020) Vol. 32, No. 2, 158-170; and <a href="https://arxiv.org/abs/2108.04662">arXiv version</a>, arXiv:2108.04662 [math.NT], 2021.
%H A373338 <a href="/index/Ch#char_fns">Index entries for characteristic functions</a>
%H A373338 <a href="/index/Pri#prime_indices">Index entries for sequences related to prime indices in the factorization of n</a>
%F A373338 a(n) = A078442(n) mod 2
%t A373338 Select[Prime@ Range@ 75, EvenQ@ Length@ NestWhileList[ PrimePi, #, PrimeQ] &]
%o A373338 (PARI) A078442(n) = my(k=0); while(isprime(n), k++; n=primepi(n)); k;
%o A373338 a(n) = A078442(n) % 2; \\ _Michel Marcus_, Jun 15 2024
%Y A373338 Cf. A333242, A262275, A348677, A078442.
%K A373338 nonn
%O A373338 1,1
%A A373338 _Michael P. May_, Jun 01 2024