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Sums s of positive exponents such that no prime of the form (3^j*5^k + 1)/2 with j + k = s exists.
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%I #8 Sep 02 2020 04:48:24

%S 2,16,24,25,30,40,41,50,57,61,64,65,69,71,74,77,79,80,82,84,89,95,97,

%T 99,104,105,106,107,111,112,119,124,129,132,133,136,137,139,141,143,

%U 147,153,155,158,165,166,167,168,170,176,177,178,181,193,203,208,215,216

%N Sums s of positive exponents such that no prime of the form (3^j*5^k + 1)/2 with j + k = s exists.

%H Robert Israel, <a href="/A337426/b337426.txt">Table of n, a(n) for n = 1..800</a>

%p filter:= proc(n) local k, p;

%p for k from 1+(n-1 mod 2) to n-1 by 2 do

%p p:= (3^(n-k)*5^k+1)/2;

%p if isprime(p) then return false fi

%p od;

%p true

%p end proc:

%p select(filter, [$2..300]); # _Robert Israel_, Sep 01 2020

%Y Positions of 0 in A337425.

%Y Cf. A336772, A337424.

%K nonn

%O 1,1

%A _Hugo Pfoertner_, Aug 27 2020