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%I #17 Jul 10 2017 02:12:17
%S 15,6,7,0,9,10,33,12,65,42,105,16,153,90,209,60,273,154,345,48,425,
%T 234,513,140,609,330,713,96,825,442,945,252,1073,570,1209,160,1353,
%U 714,1505,396,1665,874,1833,240,2009,1050,2193,572,2385,1242,2585,336,2793
%N Least common multiple of n + 4 and n - 4.
%C The recurrence for the general case lcm(n+k, n-k) is b(n) = 3*b(n-2*k) - 3*b(n-4*k) + b(n-6*k) for n>6*k.
%H Colin Barker, <a href="/A277384/b277384.txt">Table of n, a(n) for n = 1..1000</a>
%H <a href="/index/Rec#order_24">Index entries for linear recurrences with constant coefficients</a>, signature (0,0,0,0,0,0,0,3,0,0,0,0,0,0,0,-3,0,0,0,0,0,0,0,1).
%F a(n) = 3*a(n-8)-3*a(n-16)+a(n-24) for n>27.
%F G.f.: x*(15 +6*x +7*x^2 +9*x^4 +10*x^5 +33*x^6 +12*x^7 +20*x^8 +24*x^9 +84*x^10 +16*x^11 +126*x^12 +60*x^13 +110*x^14 +24*x^15 +123*x^16 +46*x^17 +51*x^18 -7*x^20 -6*x^21 -15*x^22 -4*x^23 -30*x^24 -12*x^25 -14*x^26) / ((1 -x)^3*(1 +x)^3*(1 +x^2)^3*(1 +x^4)^3).
%p A277384:=n->lcm(n+4,n-4): seq(A277384(n), n=1..100); # _Wesley Ivan Hurt_, Jul 09 2017
%t Table[LCM[n + 4, n - 4], {n, 1, 25}] (* _G. C. Greubel_, Oct 12 2016 *)
%o (PARI) a(n) = lcm(n+4, n-4)
%o (PARI) Vec(x*(15 +6*x +7*x^2 +9*x^4 +10*x^5 +33*x^6 +12*x^7 +20*x^8 +24*x^9 +84*x^10 +16*x^11 +126*x^12 +60*x^13 +110*x^14 +24*x^15 +123*x^16 +46*x^17 +51*x^18 -7*x^20 -6*x^21 -15*x^22 -4*x^23 -30*x^24 -12*x^25 -14*x^26) / ((1 -x)^3*(1 +x)^3*(1 +x^2)^3*(1 +x^4)^3) + O(x^60))
%Y Cf. A066830 (k=1), A249859 (k=2), A249860 (k=3).
%Y Cf. A277385.
%K nonn,easy
%O 1,1
%A _Colin Barker_, Oct 12 2016
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