|
Search: id:A078891
|
|
|
| A078891 |
|
Concatenate first n triangular numbers in reverse order. |
|
+0
2
|
|
| 1, 31, 631, 10631, 1510631, 211510631, 28211510631, 3628211510631, 453628211510631, 55453628211510631, 6655453628211510631, 786655453628211510631, 91786655453628211510631
(list; graph; listen)
|
|
|
OFFSET
|
1,2
|
|
|
REFERENCES
|
Shyam Sunder Gupta, Smarandache Sequence of Triangular Numbers, Smarandache Notions Journal, (to appear in Vol. 14, 2003).
|
|
LINKS
|
M. L. Perez et al., eds., Smarandache Notions Journal
|
|
EXAMPLE
|
a(3)=631 because 6,3,1 are first 3 triangular numbers in reverse order.
|
|
MATHEMATICA
|
Table[FromDigits[Flatten[IntegerDigits[Table[n*(n+1)/2, {n, m, 1, -1}]]]], {m, 1, 20}]
|
|
CROSSREFS
|
Sequence in context: A028013 A028073 A089758 this_sequence A078914 A068147 A025009
Adjacent sequences: A078888 A078889 A078890 this_sequence A078892 A078893 A078894
|
|
KEYWORD
|
base,easy,nonn
|
|
AUTHOR
|
Shyam Sunder Gupta (guptass(AT)rediffmail.com), Jan 10 2003
|
|
|
Search completed in 0.002 seconds
|
