A082221 - OEIS

%I #21 Feb 26 2021 02:09:55

%S 1,7,13,29,43,67,82,100,139,149,240,160,270,340,373,427,426,438,579,

%T 793,505,679,877,1037,820,994,1240,1268,1221,1109,1369,1487,1800,1678,

%U 1745,1607,2406,2042,2560,2356,2701,2407,2625,3127,2791,2971,3210,3170,3642

%N Main diagonal of array A082218.

%H Tanya Khovanova, <a href="http://www.tanyakhovanova.com/RecursiveSequences/NonRecursions.html">Non Recursions</a>.

%o (PARI) lista(nn) = { my(a=matrix(nn, nn)); S=Set();

%o for(s=2, nn+1, if(s%2, i0=1; i1=s-1; i2=1, i0=s-1; i1=1; i2=-1);

%o forstep(i=i0, i1, i2, j=s-i;

%o ii=sum(k=1, j-1, a[i, k]); jj=sum(k=1, i-1, a[k, j]);

%o c=chinese(Mod(ii, j), Mod(jj, i));

%o t=component(c, 1)-lift(c); while(setsearch(S, t), t+=component(c, 1));

%o a[i, j]=t; S=setunion(S, [t]);

%o if(i==j, print1(", ", sum(k=1, j, a[i, j])/j) ); ))} \\ This is a modification of _Max Alekseyev_'s PARI program from A082219. - _Petros Hadjicostas_, Feb 25 2021

%Y Cf. A082218, A082219, A082220, A082222, A082223.

%K nonn

%O 1,2

%A _Amarnath Murthy_ and Meenakshi Srikanth (menakan_s(AT)yahoo.com), Apr 09 2003

%E More terms from _Max Alekseyev_, Jun 08 2007

%E Edited by _N. J. A. Sloane_, Jun 11 2007

%E Name edited by _Petros Hadjicostas_, Feb 25 2021