login
The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A342370 a(n) = Sum_{k=1..n} gcd(k,n)^(k-1). 3
1, 3, 11, 68, 629, 7797, 117655, 2097254, 43046979, 1000000799, 25937424611, 743008402000, 23298085122493, 793714773374529, 29192926027528343, 1152921504613147242, 48661191875666868497, 2185911559739107208115, 104127350297911241532859, 5242880000000008181608132 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

LINKS

Martin Ehrenstein, Table of n, a(n) for n = 1..400

FORMULA

If p is prime, a(p) = p-1 + p^(p-1) = A173235(p).

MATHEMATICA

a[n_] := Sum[GCD[k, n]^(k - 1), {k, 1, n}]; Array[a, 20] (* Amiram Eldar, Mar 13 2021 *)

PROG

(PARI) a(n) = sum(k=1, n, gcd(k, n)^(k-1));

CROSSREFS

Cf. A000010, A018804, A056665, A173235, A341036, A342394, A342433, A342436, A342449.

Sequence in context: A218923 A342436 A342394 * A345094 A074504 A126115

Adjacent sequences:  A342367 A342368 A342369 * A342371 A342372 A342373

KEYWORD

nonn

AUTHOR

Seiichi Manyama, Mar 13 2021

EXTENSIONS

a(19) and beyond from Martin Ehrenstein, Mar 13 2021

STATUS

approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified July 30 03:08 EDT 2021. Contains 346347 sequences. (Running on oeis4.)