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a(n) = n^5 + 3n^3 + 2n = n(n^2+1)(n^2+2).
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%I #16 Aug 14 2023 12:51:43

%S 6,60,330,1224,3510,8436,17850,34320,61254,103020,165066,254040,

%T 377910,546084,769530,1060896,1434630,1907100,2496714,3224040,4111926,

%U 5185620,6472890,8004144,9812550,11934156,14408010,17276280,20584374,24381060

%N a(n) = n^5 + 3n^3 + 2n = n(n^2+1)(n^2+2).

%C Largest area of any triangle with integer sides a <= b <= c and inradius n. Triangle has sides (n^2+2, n^4+2n^2+1, n^4+3n^2+1).

%C a(n) = A002522(n)*A054602(n). - _Zerinvary Lajos_, Apr 20 2008

%H David W. Wilson, <a href="/A120573/b120573.txt">Table of n, a(n) for n = 1..10000</a>

%H <a href="/index/Rec#order_06">Index entries for linear recurrences with constant coefficients</a>, signature (6, -15, 20, -15, 6, -1).

%p with(combinat):seq(lcm(fibonacci(4,n),fibonacci(3,n)),n=1..30); # _Zerinvary Lajos_, Apr 20 2008

%t LinearRecurrence[{6,-15,20,-15,6,-1},{6,60,330,1224,3510,8436},30] (* _Harvey P. Dale_, Aug 14 2023 *)

%Y See A120062 for sequences related to integer-sided triangles with integer inradius n.

%Y Cf. A002522, A054602.

%K nonn,easy

%O 1,1

%A _David W. Wilson_, Jun 17 2006