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A171673
Numbers n with property that both n and n^2 are self numbers (A003052).
3
1, 3, 20, 86, 97, 110, 176, 187, 266, 277, 356, 367, 457, 637, 714, 716, 727, 804, 815, 894, 984, 1087, 1177, 1267, 1357, 1436, 1537, 1614, 1616, 1627, 1704, 1715, 1884, 1985, 2077, 2235, 2257, 2516, 2694, 2784, 2885, 3045, 3135, 3315, 3326, 3337, 3414
OFFSET
1,2
LINKS
Zak Seidov, A171673
MATHEMATICA
nn=1.2*10^7; list=Table[n + Total[IntegerDigits[n]], {n, nn}]; se=Complement[Range[nn], list]; se1=Select[Sqrt[se], IntegerQ[#]&]; Intersection[se, se1] (* Jayanta Basu, May 06 2013 *)
CROSSREFS
Cf. A003052 (Self or Colombian numbers), A171671 (self squares), A171672 (n^2 are self squares).
Sequence in context: A243208 A373499 A129549 * A185065 A227811 A363603
KEYWORD
base,nonn
AUTHOR
Zak Seidov, Dec 15 2009
EXTENSIONS
Changed the word "safe" in this entry to "self". - N. J. A. Sloane, Feb 26 2017
STATUS
approved