A116011 n+p(n)+p(p(n)) is a square, where p(n) is the n-th prime.

11, 106, 407, 415, 457, 5049, 11473, 13477, 15356, 18428, 19427, 20669, 27973, 39685, 40062, 45174, 58976, 60616, 66928, 93478, 105516, 108706, 113100, 118511, 139027, 163823, 170002, 178214, 184338, 206388, 217780, 222201

Offset

1,1

Links

Table of n, a(n) for n=1..32.

Example

407+p(407)+p(p(407))=169^2.

Mathematica

Select[Range[250000], IntegerQ[Sqrt[#+Prime[#]+Prime[Prime[#]]]]&] (* Harvey P. Dale, May 29 2013 *)

Crossrefs

Cf. A116010.

Sequence in context: A075183 A302925 A250416 * A229070 A365775 A058715

Adjacent sequences: A116008 A116009 A116010 * A116012 A116013 A116014

Keyword

nonn

Author

Giovanni Resta, Feb 13 2006

Status

approved