A236437 Primes which occur in their proper place in A236174.

2, 263, 269, 347, 397, 431, 461, 479, 499, 569, 599, 607, 677, 683, 719, 769, 797, 821, 929, 941, 1019, 1031, 1049, 1051, 1061, 1069, 1103, 1181, 1223, 1229, 1237, 1297, 1307, 1367, 1399, 1409, 1439, 1453, 1487, 1489, 1523, 1553, 1559, 1571, 1619, 1637, 1733, 1759, 1811, 1823, 1949, 1973, 1997

Offset: 1

Author

N. J. A. Sloane, Jan 25 2014

Keywords

• nonn
• base

Comments

Primes p such that A236174(k) = prime(k) for some k. The values of k are (essentially) given in A235377.

Same as A052033 if the initial 2 is omitted.

Examples

			263 is the 56th prime and is also the 56th term in A236174.
		

Links

• Chai Wah Wu, Table of n, a(n) for n = 1..10000

Crossrefs

Cf. A052033, A236174, A235377, A235354.

Programs

Python

from sympy import prime, isprime
def A236174(n):
    p = prime(n)
    for b in range(2,11):
        x, y, z = p, 0, 1
        while x >= b:
            x, r = divmod(x,b)
            y += r*z
            z *= 10
        y += x*z
        if isprime(y):
            return y
A236437_list = [prime(n) for n in range(1,10**6) if A236174(n) == prime(n)]
# Chai Wah Wu, Jan 03 2015