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a(n) is the largest primorial dividing A276086(n), where A276086 converts the primorial base expansion of n into its prime product form.
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%I #12 Oct 20 2019 21:45:18

%S 1,2,1,6,1,6,1,2,1,30,1,30,1,2,1,30,1,30,1,2,1,30,1,30,1,2,1,30,1,30,

%T 1,2,1,6,1,6,1,2,1,210,1,210,1,2,1,210,1,210,1,2,1,210,1,210,1,2,1,

%U 210,1,210,1,2,1,6,1,6,1,2,1,210,1,210,1,2,1,210,1,210,1,2,1,210,1,210,1,2,1,210,1,210

%N a(n) is the largest primorial dividing A276086(n), where A276086 converts the primorial base expansion of n into its prime product form.

%H Antti Karttunen, <a href="/A328580/b328580.txt">Table of n, a(n) for n = 0..2559</a>

%H <a href="/index/Pri#primorialbase">Index entries for sequences related to primorial base</a>

%F a(n) = A053589(A276086(n)).

%F a(n) = A002110(A328570(n)-1).

%F a(n) = A276086(n) / A328475(n).

%F a(n) = A276086(n) - A328476(n).

%F A328476(n) / a(n) = A328475(n) - 1.

%o (PARI) A328580(n) = { my(i=1, p=2, pr=1); while(n && (n%p), pr *= p; n = n\p; p = nextprime(1+p)); (pr); };

%Y Cf. A002110, A053589, A276086, A326810, A328475, A328476, A328570.

%K nonn

%O 0,2

%A _Antti Karttunen_, Oct 20 2019