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A089952
Numbers n such that n+1 and phi(n)+1 are both perfect squares.
1
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
MATHEMATICA
Select[Range[10^5], IntegerQ[Sqrt[ # + 1]] && IntegerQ[Sqrt[EulerPhi[ # ] + 1]] &]
CROSSREFS
Intersection of A005563 and A063530.
Sequence in context: A348730 A079721 A362812 * A373406 A295160 A240597
KEYWORD
nonn
AUTHOR
Joseph L. Pe, Jan 17 2004
STATUS
approved