A064451 LCM of totients of binomial coefficients C(n,j), j = 0..n.

1, 1, 2, 2, 4, 8, 24, 24, 72, 288, 240, 240, 1440, 2880, 2880, 11520, 23040, 46080, 207360, 276480, 82944, 829440, 2280960, 9123840, 15206400, 60825600, 273715200, 1642291200, 766402560, 7664025600, 1916006400, 1277337600

Offset

1,3

Links

Harry J. Smith, Table of n, a(n) for n = 1..200

Example

For n=4, the binomial coefficients C(4,j) are 1, 4, 6, 4, and 1. The totients are 1, 2, 2, 2, and 1.  So a(4) = lcm of 1, 2, 2, 2, 1 = 2. - Michael B. Porter, Jun 25 2018

Mathematica

Table[LCM@@Table[EulerPhi[Binomial[n, j]], {j, 0, n}], {n, 40}] (* Harvey P. Dale, Nov 04 2019 *)

Prog

(PARI) { for (n=1, 200, a=1; for (j=0, n, a=lcm(a, eulerphi(binomial(n, j)))); write("b064451.txt", n, " ", a) ) } \\ Harry J. Smith, Sep 14 2009
(PARI) a(n) = lcm(vector(n+1, k, eulerphi(binomial(n, k-1)))); \\ Michel Marcus, Jun 24 2018

Crossrefs

Cf. A002944 (see 1st comment there).

Sequence in context: A056630 A259813 A121853 * A223027 A325514 A032440

Adjacent sequences: A064448 A064449 A064450 * A064452 A064453 A064454

Keyword

nonn

Author

Labos Elemer, Oct 02 2001

Extensions

Previous Mathematica program replaced by Harvey P. Dale, Nov 04 2019

Status

approved