A292571 Lucas-Carmichael numbers whose Dedekind psi value is a square.

935, 31535, 76751, 1707839, 3106799, 11141999, 24685199, 43383167, 83618639, 151524071, 161841239, 189099039, 212133599, 213884999, 219155615, 233743319, 241485839, 271038599, 287432495, 338340239, 353107799, 624840479, 660423455, 945236159, 1171355471

Offset: 1

Author

Amiram Eldar, Sep 19 2017

Keywords

• nonn

Examples

			psi(935) = 36^2.
		

Links

• Amiram Eldar, Table of n, a(n) for n = 1..241 (terms below 10^12)

Crossrefs

Intersection of A006972 and A291167.

Cf. A001615, A272798, A292572, A292573.

Programs

Mathematica

psi[n_] := If[n < 1, 0, n*Sum[MoebiusMu[d]^2/d, {d, Divisors@n}]]; s = Import["b006972.txt","Data"][[All,-1]]; Select[s, IntegerQ@Sqrt[psi@#] &]