A118336 - OEIS

%I #12 Feb 06 2019 00:40:47

%S 1,2,4,4,10,12,16,16,18,28,30,36,40,40,42,48,58,60,64,70,72,76,78,88,

%T 96,100,100,106,108,112,124,126,136,130,148,150,156,160,162,168,178,

%U 180,190,192,196,192,204,220,226,228,228,238,240,246,252,258,268,270,276

%N a(n) = greatest multiple of (p(n+1) - p(n)) which is < p(n), where p(m) is the m-th prime.

%C A118335(n) - a(n) = 2*(p(n+1) - p(n)). A113709(n) - a(n) = p(n+1) - p(n), for n >= 2.

%F a(1)=1; a(n) = (p(n+1) - p(n))*floor(p(n)/(p(n+1)-p(n))) for n >= 2. - _Emeric Deutsch_, Apr 27 2006

%p a:=n->(ithprime(n+1)-ithprime(n))*floor(ithprime(n)/(ithprime(n+1)-ithprime(n))): 1,seq(a(n),n=2..64); # _Emeric Deutsch_, Apr 27 2006

%t Join[{1},Floor[First[#]/(Last[#]-First[#])](Last[#]-First[#])&/@Partition[Prime[ Range[ 2,60]],2,1]] (* _Harvey P. Dale_, Feb 25 2013 *)

%Y Cf. A113709, A118335.

%K nonn

%O 1,2

%A _Leroy Quet_, Apr 25 2006

%E More terms from _Emeric Deutsch_, Apr 27 2006