A235009 - OEIS

%I #9 Sep 12 2021 19:47:53

%S 61,601,63841,66553,6208513,60006553,60208513,60983449,62998657,

%T 64521217,67807489,69223681,600000001,600000409,600208513,605470081,

%U 607163929,607807489,634210201,653379481

%N Primes which become fourth powers when the digits are rotated once to the left.

%C Every term in the sequence begins with the digit 6.

%e The prime 6208513 is in the sequence because 2085136=38^4.

%t Select[Prime[Range[34*10^6]],IntegerQ[Surd[FromDigits[ RotateLeft[ IntegerDigits[ #]]],4]]&] (* _Harvey P. Dale_, Sep 12 2021 *)

%o (PARI) rotl(a) = my(b, c, d); b=#Str(a); c=floor(a/(10^(b-1))); d=a-c*(10^(b-1)); 10*d+c

%o s=[]; forprime(n=2, 700000000, if(ispower(rotl(n), 4), s=concat(s, n))); s

%Y Cf. A235008.

%K nonn,base

%O 1,1

%A _Colin Barker_, Jan 02 2014