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!)
A323486 Least number k such that the determinant of the circulant matrix formed by its decimal digits is equal to n*k. 4
1, 10168, 119700, 196, 1973082, 63980523693, 167037139360, 1350720096, 1543479071, 17239680, 4000206089, 219566358180, 104171259465, 2380649994, 113323907385, 14059155927, 19925280 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

LINKS

Table of n, a(n) for n=1..17.

Eric W. Weisstein, MathWorld: Circulant Matrix

Wikipedia, Circulant matrix

EXAMPLE

      det | 1 | = 1 = 1*1.

.

          | 1 0 1 6 8|

          | 8 1 0 1 6|

      det | 6 8 1 0 1| = 20336 = 2*10168.

          | 1 6 8 1 0|

          | 0 1 6 8 1|

MAPLE

with(linalg): P:=proc(q) local a, b, c, d, i, j, k, n, t;

for i from 1 to q do for n from 1 to q do

d:=ilog10(n)+1; a:=convert(n, base, 10); c:=[];

for k from 1 to nops(a) do c:=[op(c), a[-k]]; od; t:=[op([]), c];

for k from 2 to d do b:=[op([]), c[nops(c)]]; for j from 1 to nops(c)-1 do

b:=[op(b), c[j]]; od;  c:=b; t:=[op(t), c]; od; if i*n=det(t) then

print(n); break; fi; od; od; end: P(10^7);

CROSSREFS

Cf. A219324, A323485.

Sequence in context: A248487 A172810 A231030 * A153139 A243974 A251274

Adjacent sequences:  A323483 A323484 A323485 * A323487 A323488 A323489

KEYWORD

nonn,base,more

AUTHOR

Paolo P. Lava, Jan 17 2019

EXTENSIONS

a(6)-a(17) from Giovanni Resta, Jan 21 2019

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 23 03:11 EDT 2021. Contains 343198 sequences. (Running on oeis4.)