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 A032782 Numbers k such that k(k+1)(k+2)...(k+9) / (k+(k+1)+(k+2)+...+(k+9)) is an integer. 2

%I #22 Jul 14 2018 02:48:16

%S 0,3,6,9,13,18,20,27,36,48,63,69,90,117,118,153,198,216,279,360,363,

%T 468,603,657,846,1098,1413,1818,1980,2547,3303,4248,5949,9918,12753,

%U 17856,29763,89298

%N Numbers k such that k(k+1)(k+2)...(k+9) / (k+(k+1)+(k+2)+...+(k+9)) is an integer.

%C (d-9)/2 for divisors d >= 9 of 178605. Thus the sequence is finite. - _Robert Israel_, Jul 13 2018

%p seq((t-9)/2, t=select(`>=`,numtheory:-divisors(178605),9)); # _Robert Israel_, Jul 13 2018

%t Select[Range[0,10^5],IntegerQ[(Times@@(#+Range[0,9]))/(10#+45)]&](* _Harvey P. Dale_, Mar 18 2015 *)

%Y Cf. A032781, A032783.

%K nonn,fini,full

%O 1,2

%A _Patrick De Geest_, May 15 1998

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Last modified December 7 03:04 EST 2023. Contains 367622 sequences. (Running on oeis4.)