A242973 Positions in both e and Pi where both digits in the same position are prime.

1, 5, 9, 16, 17, 18, 25, 29, 30, 34, 40, 54, 64, 65, 74, 77, 84, 90, 92, 94, 100, 103, 112, 115, 124, 132, 136, 137, 138, 143, 144, 159, 178, 179, 180, 195, 204, 211, 217, 236, 242, 253, 275, 283, 286, 293, 302, 303, 305, 307, 317, 321, 326, 334, 339, 344, 347

Offset

1,2

Links

Jens Kruse Andersen, Table of n, a(n) for n = 1..10000

Example

Pi = 3.1415926535897932384626...
.....|....|...|......|||........
_e = 2.7182818284590452353602...

Mathematica

Module[{digs=350, p, e, th}, p=RealDigits[Pi, 10, digs][[1]]; e=RealDigits[E, 10, digs][[1]]; th = Thread[{p, e}]; Position[If[AllTrue[#, PrimeQ], 1, 0]&/@th, 1]]//Flatten (* Harvey P. Dale, Jan 28 2023 *)

Prog

(PARI) \p 1000
e=Vec(Str(exp(1)/10)); p=Vec(Str(Pi/10)); for(n=1, #e-9, if(isprime(eval(e[n+2])) && isprime(eval(p[n+2])), print1(n", "))) \\ Jens Kruse Andersen, Jul 23 2014

Crossrefs

Cf. A052055, A073302, A153031.

Sequence in context: A351826 A066081 A076856 * A315084 A315085 A315086

Adjacent sequences: A242970 A242971 A242972 * A242974 A242975 A242976

Keyword

base,nonn

Author

Philip Mizzi, May 28 2014

Extensions

Definition clarified by Harvey P. Dale, Jan 28 2023

Status

approved