login
Numbers k that are equal to 2*k when expressed in base 9 and then interpreted in base 10.
0

%I #13 Oct 26 2018 08:17:00

%S 7794416,7816758,8131871,8132006,8152638,8152650

%N Numbers k that are equal to 2*k when expressed in base 9 and then interpreted in base 10.

%e 8132006 expressed in base 9 is equal to 16264012; 16264012 = 2*8132006.

%t Select[Range[10^6, 10^7], FromDigits@ IntegerDigits[#, 9] == 2 # &] (* _Michael De Vlieger_, Oct 11 2018 *)

%o (PARI) isok(n) = fromdigits(digits(n,9), 10) == 2*n; \\ _Michel Marcus_, Sep 28 2018

%Y Cf. A139285.

%K nonn,base,fini,full

%O 1,1

%A _Anton Deynega_, Sep 28 2018