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Automorphic primes: p such that p^p ends with the digits of p.
3

%I #15 Dec 15 2017 17:34:51

%S 5,11,31,41,61,71,101,151,193,251,401,499,557,601,701,751,1151,1201,

%T 1249,1301,1601,1693,1801,1901,1951,2351,2551,2801,3001,3301,3701,

%U 4001,4201,4751,4801,4951,4999,5101,5351,5501,5701,5801,6101,6151,6301,6551

%N Automorphic primes: p such that p^p ends with the digits of p.

%H Harvey P. Dale, <a href="/A052228/b052228.txt">Table of n, a(n) for n = 1..500</a>

%e 11 is in the sequence because 11 is prime and 11^11=285311670611 ends in 11.

%t Select[ Prime@ Range@863, PowerMod[ #, #, 10^Floor[Log[10, # ] + 1]] == # &] (* _Robert G. Wilson v_ Sep 25 2006 *)

%t Select[Prime[Range[850]],PowerMod[#,#,10^IntegerLength[#]]==#&] (* _Harvey P. Dale_, Mar 05 2015 *)

%Y Cf. A003226.

%K base,nonn

%O 1,1

%A _G. L. Honaker, Jr._, Jan 30 2000

%E More terms from _Jason Earls_, Jan 02 2002