A127906 a(n) = (n in base 10) * (n in base 2).

0, 1, 20, 33, 400, 505, 660, 777, 8000, 9009, 10100, 11121, 13200, 14313, 15540, 16665, 160000, 170017, 180180, 190209, 202000, 212121, 222420, 232553, 264000, 275025, 286260, 297297, 310800, 321929, 333300, 344441, 3200000, 3300033, 3400340, 3500385

Offset: 0

Author

Ivan Baroni (estatico04(AT)yahoo.com.br), Apr 05 2007

Keywords

• nonn
• base

Comments

a(n) is a square for n=0 or a power of 4 (A000302). - Michel Marcus, Feb 20 2016

a(n) is a palindrome for n=0, 1, 3, 5, 7, 9, 33, 313, 455, 585, 819. Question: What is the next such n? If it exists it is greater than 10^9. - Michel Marcus, Feb 20 2016

Examples

			0*0, 1*1, 2*10, 3*11, 4*100, 5*101, 6*110, 7*111, 8*1000, 9*1001, 10*1010, ...
a(14) is 14*1110 = 15540.
		

Links

• Robert Israel, Table of n, a(n) for n = 0..10000

Crossrefs

Cf. A007088.

Programs

Magma

[Seqint(Intseq((n), 2))*n: n in [0..50]]; // Vincenzo Librandi, Feb 20 2016

Maple

A007088:= proc(n) option remember;
   (n mod 2) + 10 * procname(floor(n/2))
end proc:
A007088(0):= 0:
seq(n*A007088(n),n=0..100); # Robert Israel, Feb 21 2016

Mathematica

Table[n*FromDigits[IntegerDigits[n, 2]], {n, 0, 30}] (* Stefan Steinerberger, May 05 2007 *)

PARI

a(n) = n*subst(Pol(binary(n)), x, 10) ; \\ Michel Marcus, Feb 20 2016

Formula

a(n) = n*A007088(n). - Michel Marcus, Feb 21 2016

Extensions

Corrected and extended by Stefan Steinerberger, May 05 2007

Offset set to 0 by Michel Marcus, Feb 20 2016