|
|
A239831
|
|
Floor(7n^2/2) + floor(5n/2) + floor(3n/7).
|
|
1
|
|
|
5, 19, 39, 67, 101, 143, 191, 247, 308, 379, 454, 539, 628, 727, 830, 942, 1060, 1186, 1318, 1458, 1604, 1758, 1917, 2086, 2259, 2442, 2629, 2826, 3027, 3237, 3453, 3677, 3907, 4145, 4389, 4641, 4898, 5165, 5436, 5717, 6002, 6297, 6596, 6904, 7218, 7540
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
OFFSET
|
1,1
|
|
COMMENTS
|
This is a quadratic sequence.
|
|
LINKS
|
Index entries for linear recurrences with constant coefficients, signature (1,1,-1,0,0,0,1,-1,-1,1).
|
|
FORMULA
|
a(n) = +a(n-1) +a(n-2) -a(n-3) +a(n-7) -a(n-8) -a(n-9) +a(n-10). [Bruno Berselli, Mar 28 2014]
|
|
EXAMPLE
|
For n=3, a(3) = floor(7*3^2/2) + floor(5*3/2) + floor(3*3/7) = 39.
|
|
MAPLE
|
|
|
MATHEMATICA
|
Table[Floor[7 n^2/2] + Floor[5 n/2] + Floor[3 n/7], {n, 50}] (* Bruno Berselli, Mar 28 2014 *)
|
|
PROG
|
(Magma) [Floor(7*n^2/2) + Floor(5*n/2) + Floor(3*n/7): n in [1..50]]; // Vincenzo Librandi, Mar 29 2014
|
|
CROSSREFS
|
|
|
KEYWORD
|
nonn,easy
|
|
AUTHOR
|
|
|
EXTENSIONS
|
|
|
STATUS
|
approved
|
|
|
|