Square numbers which when written down and rotated by 180 degrees are unchanged.
Subsequence of squares in A000787. - Derek Orr and Michel Marcus, Aug 04 2014
Table of n, a(n) for n=1..5.
Cf. A000787, A018849 (similar sequence).
Sequence in context: A154086 A064351 A062678 * A031581 A031761 A184791
Adjacent sequences: A018845 A018846 A018847 * A018849 A018850 A018851
David W. Wilson