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A217919 Rows of A217916 in which 2's appear, when A217916 is formed into a number triangle. 3

%I

%S 1,3,5,8,10,16,19,20,23,51,54,58,70,71,103,136,139,142,145,153,161,

%T 168,169,182,204,212,219,222,224,230,232,235,240,242,276,277,286

%N Rows of A217916 in which 2's appear, when A217916 is formed into a number triangle.

%C The number 2 appears only in column 1 of A217916 (when treated as a triangle).

%F Involves triangular-indexed twin primes:

%F prime(a(n)*(a(n)-1)/2 + 1) - prime(a(n)*(a(n)-1)/2) = 2 for n>1 with a(1)=1.

%Y Cf. A217916, A217918.

%K nonn

%O 1,2

%A _Paul D. Hanna_, Mar 04 2013

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Last modified November 18 23:00 EST 2019. Contains 329305 sequences. (Running on oeis4.)