A328242 Numbers k such that A003415(A276086(k)) is a squarefree number, where A003415 is the arithmetic derivative, and A276086 is the primorial base exp-function.

1, 2, 3, 4, 5, 6, 7, 9, 10, 11, 12, 14, 15, 17, 30, 32, 33, 34, 35, 37, 38, 39, 40, 41, 42, 43, 46, 47, 60, 61, 62, 63, 65, 66, 67, 68, 69, 71, 73, 74, 75, 76, 77, 210, 211, 212, 213, 215, 217, 218, 219, 220, 221, 223, 225, 226, 227, 241, 242, 243, 245, 246, 247, 248, 249, 250, 251, 254, 255, 256, 257, 270, 273, 274, 275, 276, 277

Offset

1,2

Comments

Numbers n such that A276086(n) is either in A328234 or in A000040 (i.e., it is a prime, in which case n itself is a primorial, A002110).

Links

Antti Karttunen, Table of n, a(n) for n = 1..10681

Index entries for sequences related to primorial base

Prog

(PARI)
A327860(n) = { my(s=0, m=1, p=2, e); while(n, e = (n%p); m *= (p^e); s += (e/p); n = n\p; p = nextprime(1+p)); (s*m); };
isA328242(n) = issquarefree(A327860(n));

Crossrefs

Positions of 1's in A370130. Subsequence of A370132.

Cf. A000040, A002110, A003415, A005117, A008966, A276086, A327860, A328234.

Cf. A328241 (complement).

Cf. A328233, A328240 (subsequences).

Sequence in context: A014133 A070115 A073571 * A294295 A191852 A136416

Adjacent sequences: A328239 A328240 A328241 * A328243 A328244 A328245

Keyword

nonn

Author

Antti Karttunen, Oct 10 2019

Status

approved