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%I #15 Sep 16 2017 20:01:45
%S 0,0,1,0,0,0,0,0,1,0,0,0,0,0,0,0,0,0,0,0,1,0,0,0,0,0,1,0,0,0,0,0,0,1,
%T 1,2,2,1,1,0,2,1,1,1,1,1,0,0,0,1,1,1,3,0,0,3,2,2,1,1,1,1,2,0,5,4,4,2,
%U 4,4,0,0,4,2,4,3,1,0,1,0,1,2
%N Number of occurrences of the string n in primorial(n).
%F a(A275450(n)) > 0.
%e Primorial(3) equals 30, which contains 3 once, therefore a(3) = 1.
%t primorial[n_]:=Product[Prime[i],{i,1,n}];
%t Table[Length[StringPosition[ToString[primorial[n]],ToString[n]]],{n,1,100}]
%t SequenceCount[IntegerDigits[#[[1]]],IntegerDigits[#[[2]]]]&/@With[ {nn=90}, Thread[ {FoldList[ Times,Prime[Range[nn]]],Range[nn]}]] (* Requires Mathematica version 10 or later *) (* _Harvey P. Dale_, Sep 16 2017 *)
%Y Cf. A002110 (primorial numbers), A275450.
%K base,easy,nonn
%O 1,36
%A _Ivan N. Ianakiev_, Jul 28 2016
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