This site is supported by donations to The OEIS Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A137682 Left border of triangle A137680. 5

%I

%S 1,1,3,7,17,40,96,228,544,1296,3089,7361,17544,41810,99643,237471,

%T 565946,1348773,3214424,7660679,18257085,43510652,103695461,247129108,

%U 588963062,1403628615,3345155947,7972242937,18999609718,45280252031

%N Left border of triangle A137680.

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

%C Starting (1, 3, 7,...) = INVERT transform of A160096 [_Gary W. Adamson_, May 01 2009]

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

%e First few rows of triangle A137680 =

%e 1;

%e 1, 1;

%e 3, 0, 1;

%e 7, 2, 0, 1;

%e ...

%e 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.

%p A137682 := proc(n)

%p A137680(n,1) ;

%p end proc:

%p seq(A137682(n),n=1..30) ; # _R. J. Mathar_, Aug 12 2012

%Y Cf. A137680, A137681.

%Y Cf. A160096.

%K nonn

%O 1,3

%A _Gary W. Adamson_, Feb 05 2008

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.

Last modified October 23 11:48 EDT 2019. Contains 328345 sequences. (Running on oeis4.)