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

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A137682 Left border of triangle A137680. 5
1, 1, 3, 7, 17, 40, 96, 228, 544, 1296, 3089, 7361, 17544, 41810, 99643, 237471, 565946, 1348773, 3214424, 7660679, 18257085, 43510652, 103695461, 247129108, 588963062, 1403628615, 3345155947, 7972242937, 18999609718, 45280252031 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,3

COMMENTS

Each term in the sequence (n>1) = sum of previous terms of triangle A137680 = partial sums of sequence A137681: (1, 2, 4, 10, 23,...).

Starting (1, 3, 7,...) = INVERT transform of A160096 [Gary W. Adamson, May 01 2009]

LINKS

Table of n, a(n) for n=1..30.

FORMULA

Partial sums of sequence A137681 prefaced with a 1. a(n) = sum of all terms in rows 1 through (n-1) in triangle A137680.

EXAMPLE

First few rows of triangle A137680 =

1;

1, 1;

3, 0, 1;

7, 2, 0, 1;

...

a(5) = 17 = sum of 1 through 4 row terms of triangle A137680: (1 + 2 + 4 + 10); where (1, 2, 4, 10, 23,...) = A137681 = row sums of triangle A137680 = first difference row of A137682, n>1.

MAPLE

A137682 := proc(n)

    A137680(n, 1) ;

end proc:

seq(A137682(n), n=1..30) ; # R. J. Mathar, Aug 12 2012

CROSSREFS

Cf. A137680, A137681.

Cf. A160096.

Sequence in context: A106472 A036885 A247300 * A190360 A167213 A249753

Adjacent sequences:  A137679 A137680 A137681 * A137683 A137684 A137685

KEYWORD

nonn

AUTHOR

Gary W. Adamson, Feb 05 2008

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 June 19 13:11 EDT 2019. Contains 324222 sequences. (Running on oeis4.)