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A328829 Index of the least significant digit > 1 in the primorial base expansion of A276086(n), 0 if no such digit exists. 3
0, 0, 0, 0, 0, 3, 2, 2, 3, 0, 3, 4, 3, 3, 3, 4, 3, 5, 2, 2, 3, 4, 3, 4, 3, 3, 3, 4, 3, 4, 0, 3, 3, 3, 4, 4, 2, 2, 3, 0, 3, 5, 3, 3, 3, 5, 3, 5, 2, 2, 3, 5, 3, 5, 3, 3, 3, 5, 3, 6, 3, 4, 3, 3, 3, 3, 2, 2, 3, 5, 3, 5, 3, 3, 3, 5, 3, 5, 2, 2, 3, 5, 3, 5, 3, 3, 3, 5, 3, 5, 3, 3, 4, 3, 3, 3, 2, 2, 3, 5, 3, 5, 3, 3, 3, 5 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,6

COMMENTS

a(n) = index of the least non-unitary prime divisor of A276087(n) or 0 if no such prime-divisor exists.

LINKS

Antti Karttunen, Table of n, a(n) for n = 0..65537

Index entries for sequences related to primorial base

FORMULA

a(n) = A328828(A276086(n)) = A277885(A276087(n)).

PROG

(PARI)

A276086(n) = { my(m=1, p=2); while(n, m *= (p^(n%p)); n = n\p; p = nextprime(1+p)); (m); };

A328828(n) = { my(i=1, p=2); while(n, if((n%p)>1, return(i)); i++; n = n\p; p = nextprime(1+p)); (0); };

A328829(n) = A328828(A276086(n));

(PARI)

A277885(n) = if(1==n, 0, my(f=factor(n)); for(i=1, #f~, if(f[i, 2]>1, return(primepi(f[i, 1])))); (0));

A328829(n) = A277885(A276086(A276086(n)));

CROSSREFS

Cf. A276086, A276087, A277885, A328828, A328836 (positions of zeros).

Sequence in context: A065437 A097721 A073756 * A006379 A217956 A105198

Adjacent sequences:  A328826 A328827 A328828 * A328830 A328831 A328832

KEYWORD

nonn

AUTHOR

Antti Karttunen, Oct 29 2019

STATUS

approved

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Last modified July 29 12:41 EDT 2021. Contains 346346 sequences. (Running on oeis4.)