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A356303
The least k >= 0 such that n and A276086(n-k) are relatively prime, where A276086 is the primorial base exp-function.
4
0, 0, 0, 2, 0, 0, 0, 0, 0, 2, 6, 0, 0, 0, 0, 14, 0, 0, 0, 0, 16, 2, 0, 0, 0, 20, 0, 2, 0, 0, 0, 0, 0, 2, 0, 30, 0, 0, 0, 2, 6, 0, 18, 0, 0, 14, 0, 0, 0, 20, 16, 2, 0, 0, 0, 20, 28, 2, 0, 0, 0, 0, 0, 38, 0, 0, 0, 0, 0, 2, 66, 0, 0, 0, 0, 14, 0, 48, 0, 0, 16, 2, 0, 0, 60, 20, 0, 2, 0, 0, 0, 62, 0, 2, 0, 0, 0, 0, 70, 2, 6
OFFSET
0,4
COMMENTS
All terms are even.
PROG
(PARI)
A276086(n) = { my(m=1, p=2); while(n, m *= (p^(n%p)); n = n\p; p = nextprime(1+p)); (m); };
A356303(n) = { my(k=0); while(gcd(A276086(n-k), n)!=1, k++); (k); };
CROSSREFS
Cf. A324583 (positions of zeros).
Cf. also A356302, A356305.
Sequence in context: A028633 A316898 A351254 * A238429 A332671 A074039
KEYWORD
nonn,look
AUTHOR
Antti Karttunen, Nov 03 2022
STATUS
approved