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
Keywords
Examples
phi(332)+p(332)=2401=49^2.
Links
- Harvey P. Dale, Table of n, a(n) for n = 1..500
Programs
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Mathematica
Select[Range[25000],IntegerQ[Sqrt[EulerPhi[#]+Prime[#]]]&] (* Harvey P. Dale, Oct 05 2019 *)