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A316858 Triangle read by rows constructed from A090368 as sum of least prime factors.

%I A316858 #24 Jul 15 2018 12:54:54
%S A316858 6,8,8,10,10,10,6,12,12,6,14,8,14,8,14,16,16,10,10,16,16,6,18,18,6,18,
%T A316858 18,6,20,8,20,14,14,20,8,20,22,22,10,16,22,16,10,22,22,6,24,24,6,24,
%U A316858 24,6,24,24,6,26,8,26,20,14,26,14,20,26,8,26,8,28,10,22,28,16,16,28,22,10,28,8
%N A316858 Triangle read by rows constructed from A090368 as sum of least prime factors.
%C A316858 The greatest number in row k is 2*k + 4, thus consecutive rows identify consecutive even numbers (sums of two primes).
%C A316858 To get the n-th row: copy (1...n) of A090368, reverse, and add together.
%C A316858 When primes meet primes we get the maximum values. When primes or prime factors meet prime factors, we get lesser values. (Spot checked. Still empirical.)
%e A316858 Triangle begins:
%e A316858 { 6},         <--- copy (1,1) of A090368, add together
%e A316858 { 8,  8},     <--- copy (1,2) of A090368, reverse, and add together
%e A316858 {10, 10, 10}, <--- copy (1,3) of A090368, reverse, and add together
%e A316858 { 6, 12, 12,  6},
%e A316858 {14,  8, 14,  8, 14},
%e A316858 {16, 16, 10, 10, 16, 16},
%e A316858 { 6, 18, 18,  6, 18, 18,  6}, <=== differences from A316859 begin here
%e A316858 {20,  8, 20, 14, 14, 20,  8, 20},
%e A316858 {22, 22, 10, 16, 22, 16, 10, 22, 22},
%e A316858 { 6, 24, 24,  6, 24, 24,  6, 24, 24,  6},
%e A316858 {26,  8, 26, 20, 14, 26, 14, 20, 26,  8, 26},
%e A316858 { 8, 28, 10, 22, 28, 16, 16, 28, 22, 10, 28,  8}
%t A316858 lpf[n_] := FactorInteger[2 n + 1][[1, 1]]; A090368 = Array[lpf, 12];
%t A316858 a = Flatten[Table[A090368[[1 ;; -n]] + Reverse[A090368[[1 ;; -n]]],
%t A316858     {n, Length[A090368], 1, -1}]];
%Y A316858 Cf. A090368, A316859 (related triangle using gpfs).
%K A316858 nonn,tabl
%O A316858 1,1
%A A316858 _Fred Daniel Kline_, Jul 15 2018