A088566 Primes p such that the p-th digit in the decimal expansion of Pi is 2.

7, 17, 29, 103, 113, 137, 281, 293, 457, 463, 547, 601, 631, 823, 1051, 1091, 1109, 1201, 1231, 1283, 1301, 1327, 1399, 1427, 1447, 1487, 1523, 1621, 1663, 1733, 1847, 1907, 1949, 2099, 2141, 2281, 2297, 2309, 2377, 2767, 3023, 3037, 3119, 3121, 3391, 3457

Offset: 1

Author

Cino Hilliard, Nov 19 2003

Keywords

• nonn
• base

Examples

			In the decimal digits of Pi = 3.14159265... the first 2 occurs as the 7th digit, and 7 is prime; therefore a(1) = 7.
		

Crossrefs

Primes in A053746.

Cf. A088563 (similar for digits 0), A088565 (for digits 1),

Cf. A000796 (decimal digits of Pi).

Programs

PARI

pizeros(n,d) = { default(realprecision,5000); p = Pi; v = Vec(Str(p)); for(x=1,n, if(v[x] == Str(d) && isprime(x-1),print1(x-1",")) ) }

PARI

A088566_upto(N=3456, d=2)={localprec(N+20); [p|p<-primes([1, #N=digits(Pi\10^-N)]), N[p]==d]} \\ M. F. Hasler, Jul 28 2024