A058262 a(n) is the quotient obtained when the totient of primorial (that is, the product of p-1 values) is divided by the LCM of the same p-1 values.

1, 1, 2, 4, 8, 96, 384, 2304, 4608, 18432, 552960, 19906560, 796262400, 33443020800, 66886041600, 267544166400, 535088332800, 32105299968000, 2118949797888000, 148326485852160000, 10679506981355520000

Offset

0,3

Links

Muniru A Asiru, Table of n, a(n) for n = 0..150

Example

n=7: lcm(2-1, 3-1, 5-1, 7-1, 11-1, 13-1, 17-1) = lcm(1,2,4,6,10,12,16) = 240; phi(2*3*5*7*11*13*17) = phi(510510) = 92160 = A005867(8); a(7) = 92160/240 = 384.

Maple

with(numtheory):
nmax:=22: p:=seq([seq(ithprime(k)-1, k = 1 .. n)], n=1..nmax):
a:seq(phi(mul(ithprime(i), i=1..n))/lcm(seq(p[n][i], i=1..nops(p[n]))), n=1..nmax); # Muniru A Asiru, Jul 08 2018

Prog

(PARI) a(n) = my(v=vector(n+1, k, prime(k)-1)); prod(k=1, #v, v[k])/lcm(v); \\ Michel Marcus, Jul 08 2018

Crossrefs

Cf. A000010, A002110, A005867, A003418.

Sequence in context: A068664 A199166 A018605 * A018640 A018658 A018666

Adjacent sequences: A058259 A058260 A058261 * A058263 A058264 A058265

Keyword

nonn

Author

Labos Elemer, Dec 06 2000

Extensions

Definition revised by Editors, Jul 15 2018

Status

approved