A064467 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.

7, 1, 5, 14, 95, 111, 96, 38, 17, 187, 1, 47, 3, 24, 120, 9, 5, 220, 99, 40, 300, 14, 27, 12, 13, 853, 3487, 1488, 207, 363, 298, 1097, 860, 526, 2607, 394, 1658, 1411, 1183, 429, 439, 729, 1945, 169, 38, 705, 94, 136, 485, 186, 230, 1689, 1708, 1714, 1007, 614

Offset: 1

Author

Reinhard Zumkeller, Oct 03 2001

Keywords

• base
• nonn

Examples

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

Links

• Robert G. Wilson v, Table of n, a(n) for n = 1..1000

Crossrefs

Cf. A000040, A000796, A032445.

Programs

Mathematica

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