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A275451 Number of occurrences of the string n in primorial(n). 1

%I

%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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Last modified July 10 13:04 EDT 2020. Contains 335576 sequences. (Running on oeis4.)