A216133 In the decimal expansion of Pi, the first occurrence of these primes begins at a prime position.

7, 19, 31, 41, 43, 79, 89, 107, 137, 157, 197, 233, 263, 271, 293, 317, 367, 379, 433, 449, 479, 491, 499, 601, 641, 653, 673, 751, 757, 761, 769, 787, 797, 821, 823, 827, 853, 887

Offset: 1

Author

Vicente Izquierdo Gomez, Sep 01 2012

Keywords

• nonn
• base

Comments

We label the positions in 3.14159... so that 1 is in position 1, 4 in position 2, 1 in position 3, 5 in position 4, and so on.

Examples

			The first 19 in the decimal expansion of Pi (see A000796) starts in position 37, which is a prime.
		

Crossrefs

Cf. A000796.

Programs

Mathematica

pos_in_Pi={1,6,9,2,4,7,13,11,5,49,94,148,110,1,3,....};
s={};Do[If[PrimeQ[x]&&PrimeQ[pos_in_Pi[[x]]],AppendTo[s,pos_in_Pi]],{x,Length[v]}];s

Extensions

Edited by N. J. A. Sloane, Sep 09 2012