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A334688 Numbers missing from Pascal's spiral A334742.

%I A334688 #10 May 15 2020 13:07:06
%S A334688 9,11,13,15,16,18,19,21,22,24,25,26,28,29,30,31,33,34,35,36,38,39,40,
%T A334688 41,43,44,45,46,47,49,50,51,52,53,54,56,57,58,59,60,61,63,64,65,66,67,
%U A334688 68,70,71,72,73,74,75,76,78,79,80
%N A334688 Numbers missing from Pascal's spiral A334742.
%H A334688 Robert Israel, <a href="/A334688/b334688.txt">Table of n, a(n) for n = 1..10000</a>
%p A334688 V:= Array(-10..10,-10..10): t:=1:
%p A334688 i:= 1: j:= 0: V[0,0]:= 1: R:= NULL:
%p A334688 do
%p A334688   u:= V[i-1,j]+V[i+1,j]+V[i,j-1]+V[i,j+1];
%p A334688   V[i,j]:= u;
%p A334688   R:= R, $(t+1)..(u-1);
%p A334688   t:= u;
%p A334688   if u > 100 then break fi;
%p A334688   if  j > -i and j < i then j:= j+1
%p A334688   elif i > -j and i <= j then i:= i-1
%p A334688   elif i < j and j <= -i then j:= j-1
%p A334688   else i:= i+1
%p A334688   fi;
%p A334688 od:
%p A334688 R; # _Robert Israel_, May 15 2020
%Y A334688 Cf. A334742.
%K A334688 nonn
%O A334688 1,1
%A A334688 _N. J. A. Sloane_, May 10 2020