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A098364 Multiplication table of the digits of the square root of 2 read by antidiagonals.

%I A098364 #17 Nov 11 2021 20:07:53
%S A098364 1,4,4,1,16,1,4,4,4,4,2,16,1,16,2,1,8,4,4,8,1,3,4,2,16,2,4,3,5,12,1,8,
%T A098364 8,1,12,5,6,20,3,4,4,4,3,20,6,2,24,5,12,2,2,12,5,24,2,3,8,6,20,6,1,6,
%U A098364 20,6,8,3,7,12,2,24,10,3,3,10,24,2,12,7,3,28,3,8,12,5,9,5,12,8,3,28,3
%N A098364 Multiplication table of the digits of the square root of 2 read by antidiagonals.
%H A098364 Michel Marcus, <a href="/A098364/b098364.txt">Antidiagonals n = 1..100, flattened</a>
%F A098364 T(n,k) = A003991(A002193(n), A002193(k)). - _Michel Marcus_, Nov 03 2021
%e A098364 Triangle begins:
%e A098364   1;
%e A098364   4,4;
%e A098364   1,16,1;
%e A098364   4,4,4,4;
%e A098364   ...
%e A098364 Array begins:
%e A098364   1  4 1  4 2 ...
%e A098364   4 16 4 16 8 ...
%e A098364   1  4 1  4 2 ...
%e A098364   4 16 4 16 8 ...
%e A098364   2  8 2  8 4 ...
%e A098364   ...
%o A098364 (PARI) sqrt2(nn) = {my(r=0, x=2, list = List(), d); for(digits=1, nn, d=0; while((20*r+d)*d <= x, d++); d--; listput(list, d); x=100*(x-(20*r+d)*d); r=10*r+d;); Vec(list);} \\ A002193
%o A098364 lista(nn) = {my(dd = sqrt2(nn)); for (n=1, nn, for (k=1, n, print1(dd[k]*dd[n-k+1], ", ")));} \\ _Michel Marcus_, Nov 11 2021
%Y A098364 Cf. A002193, A003991, A098365, A098366, A098367.
%K A098364 nonn,tabl,base
%O A098364 1,2
%A A098364 Douglas Stones (dssto1(AT)student.monash.edu.au), Sep 04 2004
%E A098364 Offset changed to 1 and a(34)=1 inserted by _Georg Fischer_, Nov 02 2021