A071638 Numbers n such that phi(n) = b(n,1)^b(n,0) where b(n,1) is the number of 1's in binary representation of n and b(n,0) the number of 0's.

1, 2, 6, 10, 12, 20, 24, 34, 40, 48, 60, 68, 80, 85, 96, 136, 160, 192, 272, 320, 384, 399, 514, 544, 640, 768, 1028, 1088, 1280, 1536, 2040, 2056, 2176, 2560, 3072, 4112, 4352, 5120, 6144, 8224, 8704, 10240, 12288, 13805, 16448, 17408, 20480, 24576

Offset

1,2

Links

Table of n, a(n) for n=1..48.

Prog

(PARI) for(s=1, 100000, if(sum(i=1, length(binary(s)), if(component(binary(s), i)-1, 0, 1))^sum(i=1, length(binary(s)), if(component(binary(s), i), 0, 1))==eulerphi(s), print1(s, ", ")))

Crossrefs

Cf. A023416, A000120.

Sequence in context: A253913 A190789 A373049 * A028348 A214963 A140776

Adjacent sequences: A071635 A071636 A071637 * A071639 A071640 A071641

Keyword

easy,nonn

Author

Benoit Cloitre, Jun 22 2002

Status

approved