|
Search: id:A153783
|
|
|
| A153783 |
|
3 times 11-gonal numbers: 3n(9n-7)/2. |
|
+0
1
|
|
| 0, 3, 33, 90, 174, 285, 423, 588, 780, 999, 1245, 1518, 1818, 2145, 2499, 2880, 3288, 3723, 4185, 4674, 5190, 5733, 6303, 6900, 7524, 8175, 8853, 9558, 10290, 11049, 11835, 12648, 13488, 14355, 15249, 16170, 17118, 18093, 19095
(list; graph; listen)
|
|
|
OFFSET
|
0,2
|
|
|
FORMULA
|
a(n) = (27n^2 - 21n)/2 = A051682(n)*3.
a(n)=27*n+a(n-1)-51 (with a(1)=0) [From Vincenzo Librandi (vincenzo.librandi(AT)tin.it), Nov 14 2009]
|
|
EXAMPLE
|
For n=2, a(2)=27*2+0-51=3; n=3, a(3)=27*3+3-51=33; n=4, a(4)=27*4+33-51=90 [From Vincenzo Librandi (vincenzo.librandi(AT)tin.it), Nov 14 2009]
|
|
MATHEMATICA
|
s=0; lst={s}; Do[s+=n; AppendTo[lst, s], {n, 3, 6!, 27}]; lst [From Vladimir Orlovsky (4vladimir(AT)gmail.com), Apr 02 2009]
|
|
CROSSREFS
|
Cf. A051682, A152995.
Sequence in context: A069165 A139222 A123049 this_sequence A048911 A089015 A062215
Adjacent sequences: A153780 A153781 A153782 this_sequence A153784 A153785 A153786
|
|
KEYWORD
|
easy,nonn
|
|
AUTHOR
|
Omar E. Pol (info(AT)polprimos.com), Jan 02 2009
|
|
|
Search completed in 0.002 seconds
|
