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A218643 Array, by antidiagonals, A(n,k) = next number that is the product of exactly k primes (not necessarily distinct) after 10*n.

%I A218643 #28 Oct 28 2021 07:10:34
%S A218643 2,4,11,8,14,23,16,12,21,31,32,16,27,33,41,64,32,24,42,46,53,128,64,
%T A218643 32,36,42,51,61,256,128,64,32,54,52,62,71,512,256,128,64,48,54,63,74,
%U A218643 83,1024,512,256,128,64,72,81,75,82,97,2048,1024,512,256,128,64,72,81,92,91,101,4096,2048,1024,512,256,128,64,72,81,92,106,113,8192,4096,2048,1024,512,256,128,96,108,100,102,111,127
%N A218643 Array, by antidiagonals, A(n,k) = next number that is the product of exactly k primes (not necessarily distinct) after 10*n.
%e A218643 Table begins:
%e A218643 ========================================================
%e A218643 ...|n=0|n=1|n=2|n=3|n=4|n=5|n=6|n=7|n=7|n=9|n=10|
%e A218643 k=1|.2.|.11|.23|.31|.41|.53|.61|.71|.83|.97|.101|A218255
%e A218643 k=2|.4.|.14|.21|.33|.46|.51|.62|.74|.82|.91|.106|A185008
%e A218643 k=3|.8.|.12|.27|.42|.42|.52|.63|.75|.92|.92|.102|
%e A218643 k=4|16.|.16|.24|.36|.54|.54|.81|.81|.81|100|.104|
%e A218643 k=5|32.|.32|.32|.32|.48|.72|.72|.72|108|108|.108|
%e A218643 k=6|64.|.64|.64|.64|.64|.64|.64|.96|.96|.96|.144|
%e A218643 ========================================================
%p A218643 A218643 := proc(n,k)
%p A218643     local a;
%p A218643     for a from 10*n+1 do
%p A218643         if numtheory[bigomega](a) = k then
%p A218643             return a;
%p A218643         end if;
%p A218643     end do:
%p A218643 end proc:
%p A218643 for d from 1 to 13 do
%p A218643     for n from 0 to d-1 do
%p A218643         printf("%d,",A218643(n,d-n)) ;
%p A218643     end do:
%p A218643 end do: # _R. J. Mathar_, Nov 07 2012
%Y A218643 Cf. A008592, A218255, A185008.
%K A218643 nonn,easy,tabl
%O A218643 1,1
%A A218643 _Jonathan Vos Post_, Nov 03 2012