login
This site is supported by donations to The OEIS Foundation.
Logo

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A078891 Concatenate first n triangular numbers in reverse order. 1
1, 31, 631, 10631, 1510631, 211510631, 28211510631, 3628211510631, 453628211510631, 55453628211510631, 6655453628211510631, 786655453628211510631, 91786655453628211510631 (list; graph; refs; listen; history; internal format)
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 * A078914 A068147 A025009

Adjacent sequences:  A078888 A078889 A078890 * A078892 A078893 A078894

KEYWORD

base,easy,nonn

AUTHOR

Shyam Sunder Gupta (guptass(AT)rediffmail.com), Jan 10 2003

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Transforms | Puzzles | Hot | Classics
Recent Additions | More pages | Superseeker | Maintained by The OEIS Foundation Inc.

Content is available under The OEIS End-User License Agreement .

Last modified February 16 07:39 EST 2012. Contains 205881 sequences.