A061495 - OEIS

%I #19 Dec 23 2022 13:20:19

%S 6,60,504,660,2730,2448,7980,6072,17550,12180,32736,21420,54834,34440,

%T 85140,51888,124950,74412,175560,102660,238266,137280,314364,178920,

%U 405150,228228,511920,285852,635970,352440,778596,428640,941094,515100

%N a(n) = lcm(3n+1, 3n+2, 3n+3).

%H Harry J. Smith, <a href="/A061495/b061495.txt">Table of n, a(n) for n = 0..1000</a>

%F If n is odd, then all three factors are mutually coprime, so lcm = (3n+1)(3n+2)(3n+3), else one half that expression. - _Christopher Carl Heckman_, Sep 29 2004

%F Empirical g.f.: 6*(10*x^6+28*x^5+125*x^4+70*x^3+80*x^2+10*x+1) / ((x-1)^4*(x+1)^4). - _Colin Barker_, Feb 25 2013

%e a(0) = lcm(1,2,3) = 6; a(1) = lcm(4,5,6) = 60; etc.

%t Table[LCM@@(3n+{1,2,3}),{n,0,40}] (* _Harvey P. Dale_, Dec 23 2022 *)

%o (PARI) A061495(n)=lcm(3*n+1,lcm(3*n+2,3*n+3))

%o (PARI) { for (n=0, 1000, write("b061495.txt", n, " ", lcm(3*n+1, lcm(3*n+2, 3*n+3))) ) } \\ _Harry J. Smith_, Jul 23 2009

%K easy,nonn

%O 0,1

%A _Jason Earls_, Jun 12 2001

%E More terms from several contributors.