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A337471 Primorial inflation of n prime shifted once: a(n) = A003961(A108951(n)). 2

%I #16 Dec 08 2022 07:36:47

%S 1,3,15,9,105,45,1155,27,225,315,15015,135,255255,3465,1575,81,

%T 4849845,675,111546435,945,17325,45045,3234846615,405,11025,765765,

%U 3375,10395,100280245065,4725,3710369067405,243,225225,14549535,121275,2025,152125131763605,334639305,3828825,2835,6541380665835015,51975,307444891294245705,135135

%N Primorial inflation of n prime shifted once: a(n) = A003961(A108951(n)).

%H <a href="/index/Pri#prime_indices">Index entries for sequences computed from indices in prime factorization</a>.

%H <a href="/index/Pri#primorial_numbers">Index entries for sequences related to primorial numbers</a>.

%F a(n) = A003961(A108951(n)).

%F a(n) = A000265(A108951(A003961(n))).

%F Completely multiplicative with a(prime(i)) = A003961(A002110(i)) = A070826(1+i). - _Antti Karttunen_, Nov 17 2020

%F Sum_{n>=1} 1/a(n) = 1 / Product_{k>=2} (1 - 1/A070826(k)) = 1.6241170949... . - _Amiram Eldar_, Dec 08 2022

%o (PARI)

%o A003961(n) = my(f = factor(n)); for (i=1, #f~, f[i, 1] = nextprime(f[i, 1]+1)); factorback(f);

%o A034386(n) = prod(i=1, primepi(n), prime(i));

%o A108951(n) = { my(f=factor(n)); prod(i=1, #f~, A034386(f[i, 1])^f[i, 2]) }; \\ From A108951

%o A337471(n) = A003961(A108951(n));

%Y Row 1 of A337470.

%Y Cf. A000265, A002110, A003961, A034386, A070826, A108951.

%K nonn,mult

%O 1,2

%A _Antti Karttunen_, Aug 28 2020

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Last modified April 18 06:24 EDT 2024. Contains 371769 sequences. (Running on oeis4.)