Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).
%I #24 Jan 19 2021 05:49:22
%S 1,6,35,200,1125,6250,34375,187500,1015625,5468750,29296875,156250000,
%T 830078125,4394531250,23193359375,122070312500,640869140625,
%U 3356933593750,17547607421875,91552734375000,476837158203125
%N 5th binomial transform of (1,1,0,0,0,0,.....).
%C Main diagonal of array defined by m(1,j)=j; m(i,1)=i and m(i,j)=m(i-1,j)+4*m(i-1,j-1) - _Benoit Cloitre_, Jun 13 2003
%H <a href="/index/Rec#order_02">Index entries for linear recurrences with constant coefficients</a>, signature (10,-25).
%F a(n) = 10*a(n-1)-25*a(n-2), a(0)=1, a(1)=6.
%F a(n) = (n+5)*5^(n-1).
%F G.f.: (1-4x)/(1-5x)^2.
%F a(n) = A079027(n), n>0. - _R. J. Mathar_, Sep 18 2008
%F From _Amiram Eldar_, Jan 19 2021: (Start)
%F Sum_{n>=0} 1/a(n) = 15625*log(5/4) - 41825/12.
%F Sum_{n>=0} (-1)^n/a(n) = 15625*log(6/5) - 34175/12. (End)
%t LinearRecurrence[{10,-25},{1,6},30] (* _Harvey P. Dale_, Jan 20 2014 *)
%o (PARI) a(n)=if(n,([0,1; -25,10]^n*[1;6])[1,1],1) \\ _Charles R Greathouse IV_, Oct 07 2015
%Y Cf. A001792, A006234, A079027, A092288.
%K easy,nonn
%O 0,2
%A _Paul Barry_, Mar 07 2003