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A358221
Numbers k such that A003415(k) divides A276086(k), where A003415 is the arithmetic derivative, and A276086 is the primorial base exp-function.
9
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
Union of A000040 and A358222.
Subsequence of A358215 (thus also of A048103) and of A358229.
Positions of zeros in A328382.
Cf. A003415, A276086, A358220 (characteristic function).
Cf. also A328387, A356311, A356312.
Sequence in context: A023884 A135607 A376471 * A026453 A026455 A082984
KEYWORD
nonn
AUTHOR
Antti Karttunen, Nov 23 2022
STATUS
approved