A233455 Numbers k such that k^9 starts with k itself (in base 10).

0, 1, 10, 75, 100, 750, 1000, 4217, 7499, 10000, 100000, 177828, 1000000, 10000000, 74989421, 100000000, 1000000000, 5623413252, 10000000000, 100000000000, 177827941004, 1000000000000, 1778279410039, 10000000000000, 56234132519035, 100000000000000

Offset

1,3

Links

Table of n, a(n) for n=1..26.

G. L. Honaker, Jr. and Chris Caldwell, Prime Curios! 7499

Example

750^9 = 75084686279296875000000000 begins with 750, so 750 is in the sequence.

Mathematica

Join[{0}, Select[Range@ 1000000, Take[IntegerDigits[#^9], IntegerLength@ #] == IntegerDigits@ # &]] (* Michael De Vlieger, Aug 31 2015 *)

Prog

(PARI) r=112; print1(1, ", "); e=9; for(n=2, r, p=round((10^(1/(e-1)))^n); f=p^e; b=10^(#Str(f)-#Str(p)); if((f-lift(Mod(f, b)))/b==p, print1(p, ", ")));

Crossrefs

Cf. A052210, A052211, A233451, A233452, A233453, A233454, A233456.

Sequence in context: A119167 A233100 A266674 * A027778 A026969 A026979

Adjacent sequences: A233452 A233453 A233454 * A233456 A233457 A233458

Keyword

nonn,base,easy

Author

Arkadiusz Wesolowski, Dec 10 2013

Extensions

0 inserted by Juhani Heino, Aug 31 2015

Status

approved