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a(1) = 1, a(n+1)= a(n)*(n+1) divided by the largest prime divisor of n+1.
2

%I #9 Dec 05 2013 19:55:47

%S 1,1,1,2,2,4,4,16,48,96,96,384,384,768,2304,18432,18432,110592,110592,

%T 442368,1327104,2654208,2654208,21233664,106168320,212336640,

%U 1911029760,7644119040,7644119040,45864714240,45864714240,733835427840

%N a(1) = 1, a(n+1)= a(n)*(n+1) divided by the largest prime divisor of n+1.

%p a[1] := 1:for n from 2 to 100 do q := ifactors(n)[2]:a[n] := n*a[n-1]/q[nops(q)][1]: od:seq(a[j],j=1..100);

%t nxt[{a_,b_}]:={a(b+1)/FactorInteger[b+1][[-1,1]],b+1}; Transpose[ NestList[ nxt[#]&,{1,1},40]][[1]] (* _Harvey P. Dale_, Aug 11 2011 *)

%Y Cf. A076929.

%K nonn

%O 1,4

%A _Amarnath Murthy_, Oct 18 2002

%E Corrected and extended by _Sascha Kurz_, Jan 21 2003