A236437 - OEIS

%I #20 Mar 13 2015 00:29:25

%S 2,263,269,347,397,431,461,479,499,569,599,607,677,683,719,769,797,

%T 821,929,941,1019,1031,1049,1051,1061,1069,1103,1181,1223,1229,1237,

%U 1297,1307,1367,1399,1409,1439,1453,1487,1489,1523,1553,1559,1571,1619,1637,1733,1759,1811,1823,1949,1973,1997

%N Primes which occur in their proper place in A236174.

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

%C Same as A052033 if the initial 2 is omitted.

%H Chai Wah Wu, <a href="/A236437/b236437.txt">Table of n, a(n) for n = 1..10000</a>

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

%o (Python)

%o from sympy import prime, isprime

%o def A236174(n):

%o ....p = prime(n)

%o ....for b in range(2,11):

%o ........x, y, z = p, 0, 1

%o ........while x >= b:

%o ............x, r = divmod(x,b)

%o ............y += r*z

%o ............z *= 10

%o ........y += x*z

%o ........if isprime(y):

%o ............return y

%o A236437_list = [prime(n) for n in range(1,10**6) if A236174(n) == prime(n)]

%o # _Chai Wah Wu_, Jan 03 2015

%Y Cf. A052033, A236174, A235377, A235354.

%K nonn,base

%O 1,1

%A _N. J. A. Sloane_, Jan 25 2014