A392866 a(n) = A276086(n) mod A117366(A276086(n)), where A117366 gives the smallest prime greater than the largest prime dividing n, and A276086 is the primorial base exp-function.

1, 2, 3, 1, 4, 3, 5, 3, 1, 2, 3, 6, 4, 1, 5, 3, 1, 2, 6, 5, 4, 1, 5, 3, 2, 4, 6, 5, 4, 1, 7, 3, 10, 9, 8, 5, 2, 4, 6, 1, 7, 3, 10, 9, 8, 5, 2, 4, 6, 1, 7, 3, 10, 9, 8, 5, 2, 4, 6, 1, 5, 10, 4, 8, 1, 2, 3, 6, 9, 7, 5, 10, 4, 8, 1, 2, 3, 6, 9, 7, 5, 10, 4, 8, 1, 2, 3, 6, 9, 7, 2, 4, 6, 1, 7, 3, 10, 9, 8, 5, 2, 4

Offset

0,2

Comments

From a(30) to a(209) sequence consists of repeating subsequences, all permutations of {1..10}: 3*{7, 3, 10, 9, 8, 5, 2, 4, 6, 1}, 3*{5, 10, 4, 8, 1, 2, 3, 6, 9, 7}, 3*{2, 4, 6, 1, 7, 3, 10, 9, 8, 5}, 3*{3, 6, 9, 7, 5, 10, 4, 8, 1, 2}, 3*{10, 9, 8, 5, 2, 4, 6, 1, 7, 3}, 3*{4, 8, 1, 2, 3, 6, 9, 7, 5, 10}. However, later the subsequences are no more pure permutations, as for example a(210..221) = {11, 9, 7, 1, 8, 3, 3, 6, 9, 5, 1, 2}.

Links

Antti Karttunen, Table of n, a(n) for n = 0..30029

Index entries for sequences related to primorial base.

Formula

a(n) = A392865(A276086(n)) = A276086(n) mod A000040(1+A235224(n)).

Prog

(PARI) A392866(n) = { my(m=1, p=2); while(n, m *= (p^(n%p)); n = n\p; p = nextprime(1+p)); (m%p); };

Crossrefs

Cf. A000040, A117366, A235224, A276086, A392865.

Cf. also A391935, A391936.

Differs from analogous A392876 for the first time at n=24.

Sequence in context: A354803 A140757 A258254 * A392876 A100035 A201927

Adjacent sequences: A392863 A392864 A392865 * A392867 A392868 A392869

Keyword

nonn,base,easy

Author

Antti Karttunen, Jan 27 2026

Status

approved