A116021 phi(n) plus the n-th prime gives a square.

2, 4, 14, 27, 30, 65, 80, 113, 174, 332, 483, 498, 547, 684, 734, 737, 761, 944, 1693, 1855, 2204, 3358, 3461, 3647, 3787, 3908, 4180, 6144, 6915, 7638, 7763, 10249, 10676, 12235, 13359, 14038, 16002, 19736, 21148, 23392, 23899, 24295, 24663

Offset

1,1

Links

Harvey P. Dale, Table of n, a(n) for n = 1..500

Example

phi(332)+p(332)=2401=49^2.

Mathematica

Select[Range[25000], IntegerQ[Sqrt[EulerPhi[#]+Prime[#]]]&] (* Harvey P. Dale, Oct 05 2019 *)

Crossrefs

Cf. A116092, A116093.

Sequence in context: A047830 A036051 A115626 * A288154 A283353 A323656

Adjacent sequences: A116018 A116019 A116020 * A116022 A116023 A116024

Keyword

nonn

Author

Giovanni Resta, Feb 13 2006

Status

approved