%I #9 Sep 09 2023 11:24:22
%S 0,1,5,12,24,39,61,86,118,155,199,246,304,365,433,508,592,679,777,878,
%T 990,1109,1235,1364,1508,1657,1813,1976,2150,2327,2519,2714,2920,3133,
%U 3353,3580,3824,4071,4325,4586,4862,5141,5435,5732,6040,6359,6685,7014,7362
%N Antidiagonal sums of A365539.
%F a(n) = Sum_{m=1..n} (Sum_{k=1..m} (2*A000005(k) - 1)).
%t A365539[n_,k_]:=SeriesCoefficient[(1+x^k)/((1-x)^2*(1-x^k)),{x,0,n}]; Table[Sum[A365539[n-k,k], {k,n}], {n,0,48}] (* or *)
%t Table[Sum[Sum[2 DivisorSigma[0,k]-1,{k,m}],{m,n}],{n,0,48}]
%Y Cf. A000005, A114003 (2nd differences), A365539.
%K nonn
%O 0,3
%A _Stefano Spezia_, Sep 08 2023
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