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!)
A091398 a(n) = Product_{ p | n } (1 + Legendre(5,p) ). 2
1, 0, 0, 0, 1, 0, 0, 0, 0, 0, 2, 0, 0, 0, 0, 0, 0, 0, 2, 0, 0, 0, 0, 0, 1, 0, 0, 0, 2, 0, 2, 0, 0, 0, 0, 0, 0, 0, 0, 0, 2, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 2, 0, 0, 0, 2, 0, 2, 0, 0, 0, 0, 0, 0, 0, 0, 0, 2, 0, 0, 0, 0, 0, 0, 0, 2, 0, 0, 0, 0, 0, 0, 0, 0, 0, 2, 0, 0, 0, 0, 0, 2, 0, 0, 0, 0, 0, 2, 0, 0, 0, 0 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,11

LINKS

Andrew Howroyd, Table of n, a(n) for n = 1..1000

MAPLE

with(numtheory); L := proc(n, N) local i, t1, t2; t1 := ifactors(n)[2]; t2 := mul((1+legendre(N, t1[i][1])), i=1..nops(t1)); end; [seq(L(n, 5), n=1..120)];

MATHEMATICA

a[n_] := Times @@ (1+KroneckerSymbol[5, #]& /@ FactorInteger[n][[All, 1]]);

Array[a, 105] (* Jean-Fran├žois Alcover, Apr 08 2020 *)

PROG

(PARI) a(n)={my(f=factor(n)[, 1]); prod(i=1, #f, 1 + kronecker(5, f[i]))} \\ Andrew Howroyd, Jul 23 2018

CROSSREFS

Cf. A080891, A091379, A091396.

Sequence in context: A087781 A181009 A270599 * A062103 A112314 A280799

Adjacent sequences:  A091395 A091396 A091397 * A091399 A091400 A091401

KEYWORD

nonn,mult

AUTHOR

N. J. A. Sloane, Mar 02 2004

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 April 18 15:54 EDT 2021. Contains 343089 sequences. (Running on oeis4.)