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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

(list; graph; refs; listen; history; text; internal format)

OFFSET

1,1

COMMENTS

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

LINKS

Table of n, a(n) for n=1..52.

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

Cf. A077377, A077378, A077379, A077380.

Sequence in context: A080826 A043646 A296886 * A194565 A138026 A077030

Adjacent sequences: A077373 A077374 A077375 * A077377 A077378 A077379

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

URL: https://oeis.org/A077376

⇱ A077376 - OEIS