This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A384063 #27 Jun 04 2025 11:07:32 %S A384063 0,1,3,5,7,10,13,16,20,24,28,32,36,41,46,51,56,61,67,73,79,85,91,97, %T A384063 103,110,117,124,131,138,145,152,160,168,176,184,192,200,208,216,224, %U A384063 233,242,251,260,269,278,287,296,305,315,325,335,345,355,365,375,385,395,405,415,426,437 %N A384063 Partial sums of A172471. %H A384063 Hoang Xuan Thanh, <a href="/A384063/b384063.txt">Table of n, a(n) for n = 0..10000</a> %F A384063 a(n) = m*n - floor((m-1)*(m+3)*(2m-1)/12), where m = A172471(n). %F A384063 a(n) = m*n - A000217(m-1) - 2*A173196(m-1), where m = A172471(n). %t A384063 Accumulate[Floor[Sqrt[2*Range[0, 100]]]] (* _Paolo Xausa_, Jun 04 2025 *) %o A384063 (PARI) a(n) = sum(k=1, n, sqrtint(2*k)); \\ _Michel Marcus_, May 23 2025 %Y A384063 Cf. A172471, A173196, A000217. %K A384063 nonn %O A384063 0,3 %A A384063 _Hoang Xuan Thanh_, May 18 2025