A089952 Numbers n such that n+1 and phi(n)+1 are both perfect squares.

15, 24, 35, 143, 168, 323, 575, 675, 728, 899, 1599, 1763, 2600, 3599, 3720, 5183, 5775, 10403, 11663, 19043, 19320, 21315, 22499, 29928, 32399, 36863, 38024, 39203, 47523, 51528, 51983, 54288, 57599, 67080, 72899, 79523, 93635, 97343

Offset

1,1

Links

Amiram Eldar, Table of n, a(n) for n = 1..10000

Mathematica

Select[Range[10^5], IntegerQ[Sqrt[ # + 1]] && IntegerQ[Sqrt[EulerPhi[ # ] + 1]] &]

Crossrefs

Cf. A000010, A000290.

Intersection of A005563 and A063530.

Sequence in context: A348730 A079721 A362812 * A295160 A240597 A162964

Adjacent sequences: A089949 A089950 A089951 * A089953 A089954 A089955

Keyword

nonn

Author

Joseph L. Pe, Jan 17 2004

Status

approved