close
login
A358221
Numbers k such that A003415(k) divides A276086(k), where A003415 is the arithmetic derivative, and A276086 is the primorial base exp-function.
11
2, 3, 5, 6, 7, 9, 11, 13, 17, 19, 21, 23, 25, 26, 29, 31, 33, 37, 38, 41, 43, 46, 47, 49, 53, 59, 61, 65, 67, 71, 73, 77, 79, 83, 89, 94, 97, 101, 103, 107, 109, 113, 127, 131, 137, 139, 141, 146, 149, 151, 157, 161, 163, 167, 173, 179, 181, 185, 191, 193, 197, 199, 201, 206, 207, 209, 211, 221, 223, 227, 229, 233
OFFSET
1,1
LINKS
PROG
(PARI)
A003415(n) = if(n<=1, 0, my(f=factor(n)); n*sum(i=1, #f~, f[i, 2]/f[i, 1]));
A276086(n) = { my(m=1, p=2); while(n, m *= (p^(n%p)); n = n\p; p = nextprime(1+p)); (m); };
A358220(n) = if(n<2, 0, !(A276086(n)%A003415(n)));
isA358221(n) = A358220(n);
CROSSREFS
Cf. A003415, A276086, A358220 (characteristic function).
Subsequence of A358215 (thus also of A048103) and of A358229.
Positions of zeros in A328382.
Union of A000040 and A358222.
Other subsequences: A393071.
Cf. also A328387, A356311, A356312.
Sequence in context: A135607 A392070 A376471 * A026453 A026455 A082984
KEYWORD
nonn
AUTHOR
Antti Karttunen, Nov 23 2022
STATUS
approved