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A361215 Intersection of A361073 and 2 * A361611.

%I A361215 #34 Apr 17 2023 10:58:55
%S A361215 8,20,50,1406,1516,1558,1868,1898,1948,1978,1986,5862,5972,6014,7122,
%T A361215 7966,7996,8270,8348,8366,8548,8618,21092,31804,31822,32158,33092,
%U A361215 33162,33316,33414,37124,37190,37292,37394,39164,39214,39316,39346,39484,39562,39604,39622,39692,39794,45044,45244
%N A361215 Intersection of A361073 and 2 * A361611.
%C A361215 If A361073(j) = 2*A361611(k) then x = 2*A361611(k+1) has the property that x, x - A361073(j) and x + A361073(j) are triprimes, so x >= A361073(j+1), with equality if and only if A361073(j+1) is even.
%H A361215 Robert Israel, <a href="/A361215/b361215.txt">Table of n, a(n) for n = 1..2900</a>
%e A361215 a(4) = 1406 is a term because 1406 = A361073(20) = 2*A361611(17).
%p A361215 A:= {8}: lasta:= 8:
%p A361215 for i from 2 to 1000 do
%p A361215   for x from lasta+8 do
%p A361215     if numtheory:-bigomega(x) = 3 and numtheory:-bigomega(x-lasta) = 3 and numtheory:-bigomega(x+lasta) = 3 then
%p A361215        A:= A union {x}; lasta:= x; break
%p A361215     fi
%p A361215 od od:
%p A361215 R:= {8}: lastb:= 4:
%p A361215 while 2*lastb < lasta do
%p A361215 for x from lastb+4 do
%p A361215   if numtheory:-bigomega(x) = 2 and numtheory:-bigomega(x-lastb) = 2 and numtheory:-bigomega(x+lastb) = 2 then
%p A361215      if member(2*x,A) then R:= R union {2*x} fi;
%p A361215      lastb:= x; break
%p A361215   fi
%p A361215 od od:
%p A361215 sort(convert(R,list));
%Y A361215 Cf. A361073, A361611.
%K A361215 nonn
%O A361215 1,1
%A A361215 _Zak Seidov_ and _Robert Israel_, Apr 09 2023