|
| |
| |
|
|
|
18, 36, 58, 84, 114, 148, 186, 228, 274, 324, 378, 436, 498, 564, 634, 708, 786, 868, 954, 1044, 1138, 1236, 1338, 1444, 1554, 1668, 1786, 1908, 2034, 2164, 2298, 2436, 2578, 2724, 2874, 3028, 3186, 3348, 3514, 3684, 3858, 4036, 4218, 4404, 4594, 4788
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
|
OFFSET
|
1,1
|
|
|
COMMENTS
|
Sixth diagonal of A144562; 2*a(n)+28 is a square.
|
|
|
LINKS
|
Vincenzo Librandi, Table of n, a(n) for n = 1..1000
Index to sequences with linear recurrences with constant coefficients, signature (3,-3,1).
|
|
|
FORMULA
|
a(n)= 2*A028881(n+3). - R. J. Mathar, Jan 05 2011
G.f. -2*x*(2*x-3)*(x-3) / (x-1)^3 . - R. J. Mathar, Jan 05 2011
a(n) = 3*a(n-1) -3*a(n-2) +a(n-3). - Vincenzo Librandi, Feb 26 2012
|
|
|
MATHEMATICA
|
LinearRecurrence[{3, -3, 1}, {18, 36, 58}, 50] (* Vincenzo Librandi, Feb 26 2012
|
|
|
PROG
|
(MAGMA) I:=[18, 36, 58]; [n le 3 select I[n] else 3*Self(n-1)-3*Self(n-2)+1*Self(n-3): n in [1..40]]; // Vincenzo Librandi, Feb 26 2012
(PARI) for(n=1, 50, print1(2*n^2+12*n+4", ")); \\ Vincenzo Librandi, Feb 26 2012
|
|
|
CROSSREFS
|
Cf. A144562, A153238, A067076.
Sequence in context: A004961 A008600 A131766 * A011799 A097926 A087967
Adjacent sequences: A154572 A154573 A154574 * A154576 A154577 A154578
|
|
|
KEYWORD
|
nonn,easy
|
|
|
AUTHOR
|
Vincenzo Librandi, Jan 12 2009
|
|
|
STATUS
|
approved
|
| |
|
|
