A358222 - OEIS

The OEIS is supported by the many generous donors to the OEIS Foundation.

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).

Other ways to Give

A358222

Composite numbers k such that A003415(k) divides A276086(k), where A003415 is the arithmetic derivative, and A276086 is the primorial base exp-function.

6, 9, 21, 25, 26, 33, 38, 46, 49, 65, 77, 94, 141, 146, 161, 185, 201, 206, 207, 209, 221, 305, 321, 326, 333, 341, 346, 375, 377, 406, 413, 453, 458, 531, 581, 589, 605, 615, 689, 717, 741, 745, 746, 766, 819, 869, 893, 965, 989, 1041, 1046, 1073, 1189, 1241, 1254, 1331, 1337, 1349, 1461, 1466, 1469, 1529, 1541, 1641

(list; graph; refs; listen; history; text; internal format)

OFFSET

1,1

LINKS

Antti Karttunen, Table of n, a(n) for n = 1..10000

Index entries for sequences related to primorial base

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)));

isA358222(n) = (!isprime(n)&&A358220(n));