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A088068

Squares sandwiched between two numbers divisible by squares.

49, 1681, 1849, 3249, 6724, 8649, 9801, 11449, 13689, 13924, 20449, 24649, 28224, 37249, 42849, 57121, 59049, 63001, 66049, 85849, 94249, 106929, 110224, 117649, 127449, 135424, 154449, 165649, 190969, 196249, 208849, 243049, 257049, 265225

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OFFSET

1,1

COMMENTS

Sequence is infinite. k^2 is a member if k == 7 (mod 50), or k == -7 (mod 50).

LINKS

Table of n, a(n) for n=1..34.

EXAMPLE

49 is a term as 48 and 50 are divisible by squares.

MATHEMATICA

okQ[n_]:=Max[Transpose[FactorInteger[n]][[2]]]>1; Select[Range[600]^2, okQ[#-1]&&okQ[#+1]&] (* Harvey P. Dale, Jan 26 2011 *)

CROSSREFS

Cf. A088069.

Sequence in context: A004374 A203500 A069327 * A140394 A008843 A145848

Adjacent sequences: A088065 A088066 A088067 * A088069 A088070 A088071

KEYWORD

nonn

AUTHOR

Amarnath Murthy, Sep 22 2003

EXTENSIONS

Corrected and extended by Ray Chandler, Sep 27 2003

STATUS

approved

URL: https://oeis.org/A088068

⇱ A088068 - OEIS