|
| |
|
|
A167614
|
|
a(n) = (n^2 + 3*n + 8)/2.
|
|
4
|
|
|
|
6, 9, 13, 18, 24, 31, 39, 48, 58, 69, 81, 94, 108, 123, 139, 156, 174, 193, 213, 234, 256, 279, 303, 328, 354, 381, 409, 438, 468, 499, 531, 564, 598, 633, 669, 706, 744, 783, 823, 864, 906, 949, 993, 1038, 1084, 1131, 1179, 1228, 1278, 1329, 1381, 1434, 1488
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
|
OFFSET
|
1,1
|
|
|
LINKS
|
|
|
|
FORMULA
|
a(n) = n + a(n-1) + 1, with n>1, a(1)=6.
|
|
|
MATHEMATICA
|
CoefficientList[Series[(6 - 9 x + 4 x^2)/(1 - x)^3, {x, 0, 60}], x] (* Vincenzo Librandi, Sep 16 2013 *)
|
|
|
PROG
|
(Python)
print([n*(n+3)//2+4 for n in range(1, 60)]) # Gennady Eremin, Feb 03 2022
|
|
|
CROSSREFS
|
|
|
|
KEYWORD
|
nonn,easy
|
|
|
AUTHOR
|
|
|
|
EXTENSIONS
|
Corrected (changed one term from 1036 to 1038) by Harvey P. Dale, Mar 24 2011
|
|
|
STATUS
|
approved
|
| |
|
|
