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a(n) is the integer between p(n) and p(n+2) which is divisible by (p(n+2)-p(n)), where p(n) is the n-th prime.
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%I #22 May 30 2021 13:11:20

%S 3,4,6,12,12,18,18,20,24,32,40,42,42,50,48,56,64,70,72,72,80,80,84,96,

%T 102,102,108,108,126,126,130,136,144,144,152,156,160,170,168,176,180,

%U 192,192,198,210,216,224,228,228,230,240,240,256,252,264,264,272,280

%N a(n) is the integer between p(n) and p(n+2) which is divisible by (p(n+2)-p(n)), where p(n) is the n-th prime.

%C Exactly one integer exists between each p(n+2) and p(n) which is divisible by (p(n+2)-p(n)).

%H Harvey P. Dale, <a href="/A113728/b113728.txt">Table of n, a(n) for n = 1..1000</a>

%F a(n) = A031131(n)*ceiling(A000040(n)/A031131(n)). - _R. J. Mathar_, Aug 31 2007

%e Between the primes 19 and 29 is the composite 20 and 20 is divisible by (29-19)=10. So 20 is in the sequence.

%t For[n = 1, n < 50, n++, s := Prime[n] + 1; While[Floor[s/(Prime[n + 2] -Prime[n])] != s/(Prime[n + 2] - Prime[n]), s++ ]; Print[s]] (* _Stefan Steinerberger_, Feb 10 2006 *)

%t idp[n_]:=Module[{p1=Prime[n],p2=Prime[n+2]},Select[Range[p1+1,p2-1],Divisible[ #,p2-p1]&]]; Table[idp[n],{n,60}]//Flatten (* _Harvey P. Dale_, May 30 2021 *)

%Y Cf. A113709, A113729.

%K nonn

%O 1,1

%A _Leroy Quet_, Nov 08 2005

%E More terms from _Stefan Steinerberger_, Feb 10 2006

%E More terms from _R. J. Mathar_, Aug 31 2007