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.

A001172 Smallest even number that is an unordered sum of two odd primes in exactly n ways.

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%I A001172 M4085 N1694 #38 Dec 11 2021 11:05:25
%S A001172 0,6,10,22,34,48,60,78,84,90,114,144,120,168,180,234,246,288,240,210,
%T A001172 324,300,360,474,330,528,576,390,462,480,420,570,510,672,792,756,876,
%U A001172 714,798,690,1038,630,1008,930,780,960,870,924,900,1134,1434,840,990,1302
%N A001172 Smallest even number that is an unordered sum of two odd primes in exactly n ways.
%C A001172 a(n) = A023036(n) for all n > 1.
%D A001172 N. J. A. Sloane, A Handbook of Integer Sequences, Academic Press, 1973 (includes this sequence).
%D A001172 N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).
%H A001172 T. D. Noe, <a href="/A001172/b001172.txt">Table of n, a(n) for n = 0..10000</a>
%H A001172 Eric Wolman, <a href="/A001172/a001172.pdf">Letter to N. J. A. Sloane</a>, 1970.
%H A001172 <a href="/index/Go#Goldbach">Index entries for sequences related to Goldbach conjecture</a>
%t A001172 nn = 55; a = Table[0, {nn}]; n = 6; While[Times @@ a == 0, c = 0; k = 3; While[k <= n/2, If[PrimeQ[k] && PrimeQ[n - k], c++]; k++]; If[c <= nn && a[[c]] == 0, a[[c]] = n]; n = n + 2]; Prepend[a, 0]
%Y A001172 Cf. A000954, A000974, A002375, A005843, A023036.
%Y A001172 Divided by 2: A258713.
%K A001172 nonn,nice,look,easy
%O A001172 0,2
%A A001172 _N. J. A. Sloane_, Eric Wolman, Dec 17 1969
%E A001172 a(0) corrected by _Zak Seidov_, Sep 30 2011