OFFSET
1,1
REFERENCES
C. A. Pickover, "Keys to Infinity", New York: Wiley, p. 7, 1995.
LINKS
Harvey P. Dale, Table of n, a(n) for n = 1..1000
Eric Weisstein's World of Mathematics, Super-d Number.
MATHEMATICA
stpQ[n_]:=Module[{idn=IntegerDigits[n], id2=IntegerDigits[2n^2]}, MemberQ[ Partition[id2, 2, 1], {2, 2}]&&idn==Reverse[idn]]; Select[Range[20000], stpQ] (* Harvey P. Dale, Jan 16 2013 *)
CROSSREFS
KEYWORD
nonn,base
AUTHOR
Patrick De Geest, May 15 1998
STATUS
approved