|
| |
|
|
A156718
|
|
Numbers n such that n^2 == -1 mod 13^2.
|
|
4
|
|
|
|
70, 99, 239, 268, 408, 437, 577, 606, 746, 775, 915, 944, 1084, 1113, 1253, 1282, 1422, 1451, 1591, 1620, 1760, 1789, 1929, 1958, 2098, 2127, 2267, 2296, 2436, 2465, 2605, 2634, 2774, 2803, 2943, 2972, 3112, 3141, 3281, 3310, 3450, 3479, 3619, 3648, 3788
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
|
OFFSET
|
1,1
|
|
|
COMMENTS
|
Also, numbers of the form 169n +- 70.
|
|
|
LINKS
|
Vincenzo Librandi, Table of n, a(n) for n = 1..10000
Index to sequences with linear recurrences with constant coefficients, signature (1,1,-1).
|
|
|
FORMULA
|
a(n) = a(n-1) +a(n-2) -a(n-3).
G.f.: x*(70+29*x+70*x^2) / ( (1+x)*(x-1)^2 ). [From Alexander R. Povolotsky, Feb 15 2009]
|
|
|
MATHEMATICA
|
LinearRecurrence[{1, 1, -1}, {70, 99, 239}, 50]
|
|
|
PROG
|
(MAGMA) [Floor(n/2)*169-70*(-1)^n: n in [1..50]];
(PARI) a(n)=n\2*169-70*(-1)^n \\ Charles R Greathouse IV, Dec 23 2011
|
|
|
CROSSREFS
|
Cf. A156636, A156640, A156627, A156639.
Sequence in context: A165632 A136117 A224553 * A007621 A051971 A180274
Adjacent sequences: A156715 A156716 A156717 * A156719 A156720 A156721
|
|
|
KEYWORD
|
nonn,easy,changed
|
|
|
AUTHOR
|
Vincenzo Librandi, Feb 14 2009
|
|
|
STATUS
|
approved
|
| |
|
|
