A159001 First part "s" of A159000(n).

33, 19, 3, 5, 1209, 39, 4515, 54, 628, 695, 7, 3008, 374, 5, 17, 46, 5, 119, 1, 193933, 2438553, 24, 37, 3776, 54, 582, 1010472, 1067915, 2248, 46, 8080756, 811, 98, 10089515, 10538, 267794, 333070617, 334134, 561868, 159, 176, 1, 337435, 3, 37, 4677, 801, 101123, 13394006, 1714212, 377

Offset

1,1

Links

Table of n, a(n) for n=1..51.

Formula

a(n) = floor(A159000(n)/10^l), where l is such that phi(floor(A159000(n)/10^l)) * sigma(A159000(n)%10^l) = A159000(n). - Max Alekseyev, May 26 2025

Example

A159000(1) = 3360 = phi(33)*sigma(60) so a(1) = 33.
A159000(5) = 451584 = phi(4515)*sigma(84) so a(5) = 4515.

Crossrefs

Cf. A000010, A000203, A159000.

Sequence in context: A033353 A192631 A104781 * A304261 A022989 A023475

Adjacent sequences: A158998 A158999 A159000 * A159002 A159003 A159004

Keyword

nonn,base

Author

Farideh Firoozbakht, Jun 07 2009

Extensions

a(3), a(4), a(11) and more terms added using A159000 by Amiram Eldar, Mar 18 2024

a(34)-a(51) from Max Alekseyev, May 26 2025

Status

approved