A077376 Squarefree numbers whose internal digits form a squarefree number.

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

Author

Amarnath Murthy, Nov 06 2002

Keywords

• base
• easy
• nonn

Comments

Here 1 is treated as not squarefree. - Harvey P. Dale, Jul 22 2012

Crossrefs

Cf. A077377, A077378, A077379, A077380.

Programs

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 *)

Extensions

More terms from Harvey P. Dale, Jul 22 2012

Offset changed by Andrew Howroyd, Sep 19 2024