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Primes in Pi: a(n) = first position in decimal expansion of Pi that matches the n-th prime, or 0 if there is no such position.
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%I #10 Jun 01 2015 17:24:18

%S 7,1,5,14,95,111,96,38,17,187,1,47,3,24,120,9,5,220,99,40,300,14,27,

%T 12,13,853,3487,1488,207,363,298,1097,860,526,2607,394,1658,1411,1183,

%U 429,439,729,1945,169,38,705,94,136,485,186,230,1689,1708,1714,1007,614

%N Primes in Pi: a(n) = first position in decimal expansion of Pi that matches the n-th prime, or 0 if there is no such position.

%H Robert G. Wilson v, <a href="/A064467/b064467.txt">Table of n, a(n) for n = 1..1000</a>

%e A000040(4) = 7 = A000796(14) and A000796(i) <> 7 for i < 14, so a(4) = 14.

%t pi = ToString[ N[ Pi, 4000]]; pi = StringDrop[pi, {2}]; Table[ StringPosition[pi, ToString[ Prime[ n]], 1][[1, 1]], {n, 60}]

%t With[{pidg=RealDigits[Pi,10,5000[[1]]},Table[SequencePosition[ pidg, IntegerDigits[ n]][[1,1]],{n,Prime[ Range[ 60]]}]] (* The program uses the SequencePosition function from Mathematica version 10 *) (* _Harvey P. Dale_, Jun 01 2015 *)

%Y Cf. A000040, A000796, A032445.

%K base,nonn

%O 1,1

%A _Reinhard Zumkeller_, Oct 03 2001