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

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A115650 Triangular numbers which are the sum of distinct double factorials (A006882). 2
1, 3, 6, 10, 15, 21, 28, 66, 105, 120, 153, 171, 435, 561, 946, 1378, 1485, 3916, 4005, 4278, 4851, 4950, 11781, 14365, 15576, 47586, 50086, 51360, 57970, 60378, 60726, 61425, 61776, 139128, 145530, 146070, 149878, 150426, 182710, 659526, 702705 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

Double factorials 0!! and 1!! are not considered distinct. Note that double factorial (n!!) is different from (n!)!.

LINKS

Table of n, a(n) for n=1..41.

EXAMPLE

T(527) = 19128 = 13!! + 10!! + 7!! + 6!!.

CROSSREFS

Cf. A006882, A115648, A115649.

Sequence in context: A117520 A147846 A062099 * A025745 A175724 A101551

Adjacent sequences:  A115647 A115648 A115649 * A115651 A115652 A115653

KEYWORD

nonn

AUTHOR

Giovanni Resta, Jan 28 2006

STATUS

approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified August 21 06:14 EDT 2019. Contains 326162 sequences. (Running on oeis4.)