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 A142074 #9 Aug 11 2017 13:05:18
%S A142074 12,35,81,147,213,321,411,477,589,677,783,873,987,1113,1179,1257,1447,
%T A142074 1539,1667,1797,1909,2001,2127,2201,2457,2523,2631,2767,2899,2987,
%U A142074 3093,3237,3423,3501,3717,3843,3957,4109,4219,4371
%N A142074 Prime number superposition a(n) = 10*A008578(2n-1) + A008578(2n).
%C A142074 The two factors 10 and 1 of this linear combination could be replaced by any other pair of integers.
%F A142074 a(n) = 10*prime(2n-2)+prime(2n-1), n>1.
%p A142074 A008578 := proc(n) if n = 1 then 1; else ithprime(n-1) ; end if; end proc:
%p A142074 A142074 := proc(n) 10*A008578(2*n-1)+A008578(2*n) ; end proc: # _R. J. Mathar_, Jul 07 2011
%t A142074 Join[{12},10#[[1]]+#[[2]]&/@Partition[Prime[Range[2,80]],2]] (* _Harvey P. Dale_, Aug 11 2017 *)
%K A142074 nonn,easy,less
%O A142074 1,1
%A A142074 _Paul Curtz_, Sep 15 2008