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a(n) = lcm(prime(n)+1, prime(n+1)+1) / 2.
0

%I #8 Mar 04 2018 17:43:43

%S 6,6,12,12,42,63,90,60,60,240,304,399,462,264,216,270,930,1054,612,

%T 1332,1480,840,630,2205,2499,2652,1404,2970,3135,3648,2112,1518,4830,

%U 1050,5700,6004,6478,3444,2436,2610,8190,8736,9312,9603,9900,5300,5936,6384

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

%F a(n) = (1/2)*lcm(1+A000040(n), 1+A000040(1+n)).

%t f[n_] := LCM [Prime[n] + 1, Prime[n + 1] + 1]/2; Table[f@n, {n, 48}] (* _Robert G. Wilson v_, Jun 28 2007 *)

%K easy,nonn

%O 1,1

%A Philippe LALLOUET (philip.lallouet(AT)wanadoo.fr), Jun 26 2007

%E More terms from _Robert G. Wilson v_, Jun 28 2007