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%I A324350 #12 Feb 26 2019 08:19:06
%S A324350 1,1,1,1,2,1,1,1,1,1,1,2,3,2,1,1,1,3,3,1,1,1,2,3,6,3,2,1,1,1,3,3,3,3,
%T A324350 1,1,1,2,1,6,9,6,1,2,1,1,1,1,1,9,9,1,1,1,1,1,2,3,2,1,18,1,2,3,2,1,1,1,
%U A324350 3,3,1,1,1,1,3,3,1,1,1,2,3,6,3,2,5,2,3,6,3,2,1,1,1,3,3,3,3,5,5,3,3,3,3,1,1,1,2,1,6,9,6,5,10,5,6,9,6,1,2,1
%N A324350 Square array read by antidiagonals: A(x,y) = gcd(A276086(x),A276086(y)), for x, y >= 0.
%H A324350 Antti Karttunen, <a href="/A324350/b324350.txt">Table of n, a(n) for n = 0..7259 (the first 120 antidiagonals of the array)</a>
%H A324350 Antti Karttunen, <a href="/A324350/a324350.txt">Data supplement: n, a(n) computed for n = 0..65702</a>
%H A324350 <a href="/index/Pri#primorialbase">Index entries for sequences related to primorial base</a>
%F A324350 A(x,y) = gcd(A276086(x), A276086(y)).
%F A324350 A(x,y) = A276086(A324351(x,y)).
%e A324350 The array A begins:
%e A324350        0   1   2   3   4   5   6   7   8   9  10  11  12
%e A324350   x/y  ------------------------------------------------------
%e A324350    0:  1,  1,  1,  1,  1,  1,  1,  1,  1,  1,  1,  1,  1, ...
%e A324350    1:  1,  2,  1,  2,  1,  2,  1,  2,  1,  2,  1,  2,  1, ...
%e A324350    2:  1,  1,  3,  3,  3,  3,  1,  1,  3,  3,  3,  3,  1, ...
%e A324350    3:  1,  2,  3,  6,  3,  6,  1,  2,  3,  6,  3,  6,  1, ...
%e A324350    4:  1,  1,  3,  3,  9,  9,  1,  1,  3,  3,  9,  9,  1, ...
%e A324350    5:  1,  2,  3,  6,  9, 18,  1,  2,  3,  6,  9, 18,  1, ...
%e A324350    6:  1,  1,  1,  1,  1,  1,  5,  5,  5,  5,  5,  5,  5, ...
%e A324350    7:  1,  2,  1,  2,  1,  2,  5, 10,  5, 10,  5, 10,  5, ...
%e A324350    8:  1,  1,  3,  3,  3,  3,  5,  5, 15, 15, 15, 15,  5, ...
%e A324350    9:  1,  2,  3,  6,  3,  6,  5, 10, 15, 30, 15, 30,  5, ...
%e A324350   10:  1,  1,  3,  3,  9,  9,  5,  5, 15, 15, 45, 45,  5, ...
%e A324350   11:  1,  2,  3,  6,  9, 18,  5, 10, 15, 30, 45, 90,  5, ...
%e A324350   12:  1,  1,  1,  1,  1,  1,  5,  5,  5,  5,  5,  5, 25, ...
%o A324350 (PARI)
%o A324350 up_to = 65703; \\ = binomial(362+1,2)
%o A324350 A276086(n) = { my(i=0,m=1,pr=1,nextpr); while((n>0),i=i+1; nextpr = prime(i)*pr; if((n%nextpr),m*=(prime(i)^((n%nextpr)/pr));n-=(n%nextpr));pr=nextpr); m; };
%o A324350 A324350sq(row,col) = gcd(A276086(row),A276086(col));
%o A324350 A324350list(up_to) = { my(v = vector(up_to), i=0); for(a=0,oo, for(col=0,a, if(i++ > up_to, return(v)); v[i] = A324350sq(a-col,col))); (v); };
%o A324350 v324350 = A324350list(up_to);
%o A324350 A324350(n) = v324350[1+n];
%Y A324350 Cf. A003989, A276086 (central diagonal), A324198, A324351.
%K A324350 nonn,tabl
%O A324350 0,5
%A A324350 _Antti Karttunen_, Feb 25 2019

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