cp's OEIS Frontend

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.

A051035 Composite numbers which can be represented as the sum of two primes (i.e., A002808 excluding A025583).

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%I A051035 #16 Feb 16 2025 08:32:41
%S A051035 4,6,8,9,10,12,14,15,16,18,20,21,22,24,25,26,28,30,32,33,34,36,38,39,
%T A051035 40,42,44,45,46,48,49,50,52,54,55,56,58,60,62,63,64,66,68,69,70,72,74,
%U A051035 75,76,78,80,81,82,84,85,86,88,90,91,92,94,96,98,99,100,102,104,105
%N A051035 Composite numbers which can be represented as the sum of two primes (i.e., A002808 excluding A025583).
%H A051035 Reinhard Zumkeller, <a href="/A051035/b051035.txt">Table of n, a(n) for n = 1..10000</a>
%H A051035 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/PrimePartition.html">Prime Partition.</a>
%t A051035 r[n_] := Reduce[2 <= p <= q && n == p + q, {p, q}, Primes]; Select[Range[4, 105], r[#] =!= False && ! PrimeQ[#] & ] (* _Jean-François Alcover_, Oct 29 2012 *)
%o A051035 (Haskell)
%o A051035 a051035 n = a051035_list !! (n-1)
%o A051035 a051035_list = filter ((== 0) . a010051) a014091_list
%Y A051035 Cf. A002808, A025583.
%Y A051035 Cf. A010051, subsequence of A014092.
%K A051035 nonn
%O A051035 1,1
%A A051035 _Eric W. Weisstein_