A063474 Half totient of 2^n+1.

1, 2, 3, 8, 10, 24, 42, 128, 162, 400, 682, 1920, 2730, 6272, 9900, 32768, 43690, 93312, 174762, 493440, 682668, 1672704, 2796202, 8257536, 10125000, 26153088, 42384060, 126322560, 175923744, 380160000, 715827882, 2144133120

Offset

1,2

Links

Harry J. Smith, Table of n, a(n) for n = 1..250

Formula

a(n) = A023022(A000051(n)).

Prog

(PARI) H(n)=eulerphi(n)/2; j=[]; for(n=1, 40, j=concat(j, H(2^n+1))); j
(PARI) { for (n=1, 250, write("b063474.txt", n, " ", eulerphi(2^n + 1)/2) ) } \\ Harry J. Smith, Aug 22 2009

Crossrefs

Cf. A023022, A000051.

Sequence in context: A175715 A329582 A138880 * A163492 A025562 A218910

Adjacent sequences: A063471 A063472 A063473 * A063475 A063476 A063477

Keyword

nonn

Author

Jason Earls, Jul 27 2001

Status

approved