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A077376
Squarefree numbers whose internal digits form a squarefree number.
4
122, 123, 127, 129, 130, 131, 133, 134, 137, 138, 139, 151, 154, 155, 157, 158, 159, 161, 163, 165, 166, 167, 170, 173, 174, 177, 178, 179, 221, 222, 223, 226, 227, 229, 230, 231, 233, 235, 237, 238, 239, 251, 253, 254, 255, 257, 258, 259, 262, 263, 265, 266
OFFSET
1,1
COMMENTS
Here 1 is treated as not squarefree. - Harvey P. Dale, Jul 22 2012
MATHEMATICA
sf2Q[n_]:=Module[{c=FromDigits[Most[Rest[IntegerDigits[n]]]]}, c!=1&&SquareFreeQ[ n]&&SquareFreeQ[c]]; Select[Range[100, 300], sf2Q] (* Harvey P. Dale, Jul 22 2012 *)
CROSSREFS
KEYWORD
base,easy,nonn
AUTHOR
Amarnath Murthy, Nov 06 2002
EXTENSIONS
More terms from Harvey P. Dale, Jul 22 2012
Offset changed by Andrew Howroyd, Sep 19 2024
STATUS
approved