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

 

Logo

Please make a donation to keep the OEIS running. We are now in our 55th year. In the past year we added 12000 new sequences and reached 8000 citations (which often say "discovered thanks to the OEIS"). We need to raise money to hire someone to manage submissions, which would reduce the load on our editors and speed up editing.
Other ways to donate

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A207321 Partial sums of A002893. 0
0, 3, 18, 111, 750, 5403, 40572, 313407, 2471166, 19791003, 160459068, 1313922063, 10847561088, 90174127683, 754009158018, 6336733626111, 53489159252670, 453258909448635, 3854034482891724, 32871004555812111, 281127047928811200, 2410285909684370787, 20711470169495359602, 178337708176330555839 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

LINKS

Table of n, a(n) for n=0..23.

Z.-W. Sun, Congruences for Franel numbers, arXiv preprint arXiv:1112.1034, 2011.

FORMULA

n^2*a(n) +(-11*n^2+10*n-3)*a(n-1) +(19*n^2-28*n+12)*a(n-2) -9*(n-1)^2*a(n-3)=0. - R. J. Mathar, Aug 25 2013

a(n) ~ 3^(2*n + 7/2) / (32*Pi*n). - Vaclav Kotesovec, Mar 30 2018

MATHEMATICA

Table[Sum[HypergeometricPFQ[{1/2, -k, -k}, {1, 1}, 4], {k, 1, n}], {n, 0, 20}] (* Vaclav Kotesovec, Mar 30 2018 *)

CROSSREFS

Sequence in context: A114311 A134092 A000274 * A193236 A215047 A213099

Adjacent sequences:  A207318 A207319 A207320 * A207322 A207323 A207324

KEYWORD

nonn

AUTHOR

N. J. A. Sloane, Feb 16 2012

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 December 8 14:38 EST 2019. Contains 329865 sequences. (Running on oeis4.)