This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A171743 #14 Nov 24 2019 02:34:43
%S A171743 4,4,4,6,8,8,12,12,24,16,32,24,24,24,40,48,32,64,44,48,72,54,84,60,60,
%T A171743 64,48,72,72,64,84,132,88,96,80,120,128,80,128,160,96,120,128,96,120,
%U A171743 160,180,120,144,120,232,128,160,252,192,216,144,272,180,184,192,160
%N A171743 a(n) = A000010(A001043(n)).
%F A171743 a(n) = phi(prime(n) + prime(n+1)).
%p A171743 A000010 := proc(n) numtheory[phi](n); end proc: A001043 := proc(n) ithprime(n)+ithprime(n+1) ; end proc: A171743 := proc(n) A000010(A001043(n)) ; end proc: for n from 1 to 100 do printf("%d,", A171743(n)) ; od: # _R. J. Mathar_, Jan 21 2010
%t A171743 EulerPhi[Total[#]]&/@Partition[Prime[Range[70]],2,1] (* _Harvey P. Dale_, Mar 05 2013 *)
%o A171743 (PARI) p=2;forprime(q=3,1e3,print1((p-1)*(q-1)", ");p=q) \\ _Charles R Greathouse IV_, Feb 21 2013
%Y A171743 Cf. A000010, A001043.
%K A171743 easy,nonn
%O A171743 1,1
%A A171743 _Giovanni Teofilatto_, Dec 17 2009
%E A171743 Corrected (a(36)=204 removed) by _R. J. Mathar_, Jan 21 2010