A217842 Product of the numbers p such that phi(p) = n, where phi is Euler's totient function.

2, 72, 1, 4800, 1, 15876, 1, 3456000, 1, 242, 1, 300500928, 1, 1, 1, 2130739200, 1, 1052676, 1, 119790000, 1, 1058, 1, 531598161669120000, 1, 1, 1, 1682, 1, 1922, 1, 20864198246400, 1, 1, 1, 1159208596538496, 1, 1, 1, 265804426800000000, 1, 17757796, 1

Offset

1,1

Comments

It appears that all terms greater than 1 are distinct. This is true for all n <= 10^6.

Links

T. D. Noe, Table of n, a(n) for n = 1..1000

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

David M. Bressoud, A Course in Computational Number Theory (web page), CNT.m, Computational Number Theory Mathematica package.

Mathematica

Needs["CNT`"]; Table[Times @@ PhiInverse[n], {n, 100}]

Prog

(PARI) a(n) = vecprod(invphi(n)); \\ Amiram Eldar, Nov 15 2024, using Max Alekseyev's invphi.gp

Crossrefs

Cf. A002181 (smallest inverse), A006511 (largest inverse), A215240 (sum of inverses).

Cf. A032447 (inverse of phi).

Sequence in context: A055030 A361688 A185120 * A053318 A272757 A187707

Adjacent sequences: A217839 A217840 A217841 * A217843 A217844 A217845

Keyword

nonn,changed

Author

T. D. Noe, Oct 12 2012

Status

approved