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A261215 Triangle read by rows: T(n, k) is the number of squarefree integers x such that x<=primorial(n) and omega(n) = k with 0<=k<=n.

%I A261215 #14 Aug 12 2015 13:01:06
%S A261215 1,1,1,1,3,1,1,10,7,1,1,46,62,19,1,1,343,643,359,58,1,1,3248,7429,
%T A261215 5723,1708,152,1,1,42331,110373,104928,44365,7926,422,1,1,646029,
%U A261215 1848729,2024368,1068664,276833,31108,995,1
%N A261215 Triangle read by rows: T(n, k) is the number of squarefree integers x such that x<=primorial(n) and omega(n) = k with 0<=k<=n.
%H A261215 Giovanni Resta, <a href="/A261215/b261215.txt">Table of n, a(n) for n = 0..77</a>
%e A261215 Triangle begins:
%e A261215 1;
%e A261215 1, 1;
%e A261215 1, 3, 1;
%e A261215 1, 10, 7, 1;
%e A261215 1, 46, 62, 19, 1;
%e A261215 1, 343, 643, 359, 58, 1;
%e A261215 ...
%o A261215 (PARI) primo(n) = prod(i=1, n, prime(i));
%o A261215 tabl(nn) = {v = vector(1); na = 1; for (n=0, nn, nb = primo(n); for (i=na, primo(n), if (issquarefree(i), v[1+omega(i)]++);); print(v); v = concat(v, 0); na = nb + 1;);}
%Y A261215 Cf. A002110 (primorials), A000849 (1st column), A001221 (omega), A005117 (squarefrees), A092479 (similar triangle).
%K A261215 nonn,tabl
%O A261215 0,5
%A A261215 _Michel Marcus_, Aug 12 2015