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a(n) = least k such that 1+2+...+k >= 1^3 + 2^3 + ... + n^3.
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%I #11 Jun 19 2024 14:50:16

%S 1,4,8,14,21,30,40,51,64,78,93,110,129,148,170,192,216,242,269,297,

%T 327,358,390,424,460,496,535,574,615,658,701,747,793,841,891,942,994,

%U 1048,1103,1160,1218,1277,1338,1400,1464,1529,1595,1663,1732,1803,1875

%N a(n) = least k such that 1+2+...+k >= 1^3 + 2^3 + ... + n^3.

%F a(n) = round(sqrt(1/2)*n*(n+1)). - _Ralf Stephan_, Jan 24 2003

%o (PARI) for(n=1,100,print1(round(sqrt(1/2)*n*(n+1))",")).

%o (Python)

%o from math import isqrt

%o def A027924(n): return isqrt((n*(n+1))**2<<1)+1>>1 # _Chai Wah Wu_, Jun 19 2024

%Y Cf. A000537.

%K nonn

%O 1,2

%A _Clark Kimberling_

%E More terms from _Ralf Stephan_, Jan 24 2003