A071634 Number of terms in the set InvPhi(1048576*prime(n)), where prime(n) is the n-th prime.

23, 112, 81, 64, 75, 48, 36, 28, 43, 68, 14, 80, 35, 50, 0, 43, 28, 28, 46, 52, 44, 32, 38, 49, 48, 37, 10, 34, 24, 47, 34, 65, 19, 28, 59, 20, 32, 82, 15, 30, 61, 32, 48, 62, 10, 32, 2, 26, 18, 16, 65, 77, 0, 46, 8, 0, 43, 18, 56, 60, 0, 38, 40, 13, 36, 26, 44, 46, 41, 12, 0

Offset

1,1

Links

Donovan Johnson, Table of n, a(n) for n = 1..1000

Max Alekseyev, PARI/GP Scripts for Miscellaneous Math Problems (invphi.gp).

Example

InvPhi(1048576*211) = {221249537,442499074}, a(47) = 2.
Observe that a(15) = 0 because 47 needs a very large 2^i multiplier (instead of 1048576) to give a nonempty InvPhi set.

Maple

>[seq(nops(invphi(1048576*ithprime(i))), i=1..128)];

Prog

(PARI) a(n) = invphiNum(1048576 * prime(n)); \\ Amiram Eldar, Nov 11 2024, using Max Alekseyev's invphi.gp

Crossrefs

Cf. A000010, A002202, A005277, A007617, A058888, A071629, A071630, A071631, A071632, A071633.

Sequence in context: A126410 A356877 A260986 * A234252 A101804 A142324

Adjacent sequences: A071631 A071632 A071633 * A071635 A071636 A071637

Keyword

nonn

Author

Labos Elemer, May 30 2002

Status

approved