A071630 Number of terms in the set InvPhi(8*prime(n)), where prime(n) is the n-th prime.
6, 10, 9, 3, 6, 3, 2, 0, 4, 6, 0, 3, 4, 3, 0, 4, 0, 0, 3, 2, 3, 3, 4, 4, 3, 2, 0, 2, 0, 4, 3, 6, 2, 3, 2, 0, 0, 3, 0, 4, 6, 0, 4, 3, 0, 3, 0, 0, 0, 0, 4, 6, 0, 4, 0, 0, 2, 0, 3, 4, 0, 4, 3, 0, 0, 0, 0, 0, 2, 0, 0, 4, 0, 3, 0, 0, 0, 0, 2, 3, 4, 0, 6, 3, 0, 4, 2, 0, 0, 0, 0, 2, 3, 6, 3, 0, 6, 0, 0, 0, 0, 2, 0, 0
Offset: 1
Keywords
Examples
For n=5: invphi(8*11) = {89,115,178,184,230,276}, a(5) = 6.
Links
- Amiram Eldar, Table of n, a(n) for n = 1..10000 (terms 1..1000 from Donovan Johnson)
- Max Alekseyev, PARI/GP Scripts for Miscellaneous Math Problems (invphi.gp).
Programs
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Maple
[seq(nops(invphi(8*ithprime(i))),i=1..128)];
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PARI
a(n) = invphiNum(8*prime(n)); \\ Amiram Eldar, Nov 07 2024, using Max Alekseyev's invphi.gp