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A136310 a(n)=a(n-1)*(2^K)+ n*(n+1)/2 ; a(0)=1; K=floor(log_2 n*(n+1)/2). 1
1, 2, 7, 34, 282, 2271, 36357, 581740, 18615716, 595702957, 19062494679, 1219999659522, 78079978209486, 4997118605407195, 319815590746060585, 20468197807747877560, 2619929319391728327816, 335350952882141225960601, 42924921968914076922957099 (list; graph; refs; listen; history; text; internal format)
OFFSET
0,2
LINKS
MAPLE
A136310 := proc(n)
option remember;
if n = 0 then
1;
else
k := floor(log[2](n*(n+1)/2)) ;
procname(n-1)*2^k + n*(n+1)/2 ;
end if;
end proc:
seq(A136310(n), n=0..10) ; # R. J. Mathar, Jun 19 2021
MATHEMATICA
nxt[{n_, a_}]:=Module[{c=((n+1)(n+2))/2}, {n+1, a*2^Floor[Log[2, c]]+c}]; NestList[nxt, {0, 1}, 20][[All, 2]] (* Harvey P. Dale, May 13 2018 *)
CROSSREFS
Sequence in context: A029894 A110313 A000944 * A222868 A222777 A222891
KEYWORD
easy,nonn
AUTHOR
Ctibor O. Zizka, Mar 22 2008
EXTENSIONS
More terms from Harvey P. Dale, May 13 2018
Offset corrected. - R. J. Mathar, Jun 19 2021
STATUS
approved

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Last modified March 29 11:14 EDT 2024. Contains 371278 sequences. (Running on oeis4.)