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A124809 Numbers of the form (square + 1) that are not squarefree. 8
50, 325, 1025, 1445, 1682, 1850, 3250, 4625, 4901, 6725, 8650, 9802, 11450, 13690, 13925, 17425, 20450, 24650, 28225, 33125, 37250, 42850, 47525, 53825, 57122, 59050, 63002, 66050, 71825, 79525, 85850, 94250, 101125, 106930, 110225, 117650 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

The sequence is infinite (see comment in A049532). - Emmanuel Vantieghem, Oct 25 2016

LINKS

Harvey P. Dale, Table of n, a(n) for n = 1..1000

FORMULA

a(n) = A049532(n)^2 + 1.

MATHEMATICA

Select[Range[400]^2+1, !SquareFreeQ[#]&] (* Harvey P. Dale, Sep 15 2016 *)

PROG

(MAGMA) [n^2+1: n in [1..500]| not IsSquarefree(n^2+1)]; // Vincenzo Librandi, Oct 26 2016

CROSSREFS

Cf. A002522, A013929, A049532, A069987.

Sequence in context: A183698 A183690 A221572 * A261803 A184564 A184556

Adjacent sequences:  A124806 A124807 A124808 * A124810 A124811 A124812

KEYWORD

nonn

AUTHOR

Reinhard Zumkeller, Nov 08 2006

STATUS

approved

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Last modified September 22 00:25 EDT 2017. Contains 292326 sequences.