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 #7 May 28 2015 09:46:48
%S 1,2,6,9,5,6,18,16,26,10,5,17,52,43,54,1,62,54,73,125,81,63,77,129,49,
%T 185,180,7,79,204,145,128,159,244,97,296,250,257,323,97,286,168,106,
%U 106,174,316,83,377,279,250,296,423,92,384,199
%N Let R(i,j) be the rectangle with antidiagonals 1; 2,3; 4,5,6; ...; each k is an R(i(k),j(k)) and A057052(n) = i(n^3).
%H Ivan Neretin, <a href="/A057052/b057052.txt">Table of n, a(n) for n = 1..10000</a>
%t # - (l = Floor[Sqrt[2 #] - 1/2]) (l + 1)/2 & /@ ((Range@55)^3) (* _Ivan Neretin_, May 28 2015 *)
%Y Cf. A002260 = i(n), A057049 = i(n^2).
%K nonn
%O 1,2
%A _Clark Kimberling_, Jul 30 2000