cp's OEIS Frontend

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.

A162362 a(n) = A066186(n) - A004125(n).

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%I A162362 #7 Oct 22 2023 18:23:27
%S A162362 1,4,8,19,31,63,97,168,258,407,594,907,1285,1859,2604,3660,4998,6883,
%T A162362 9246,12479,16562,21967,28767,37715,48847,63224,81145,103980,132234,
%U A162362 167982,211935,267001,334535,418343,520687,646974,800336,988322
%N A162362 a(n) = A066186(n) - A004125(n).
%e A162362 1(=1-0), 4(=4-0), 8(=9-1), 19(=20-1), 31(=35-4), 63(=66-3), 97(=105-8), etc.
%o A162362 (Python)
%o A162362 from math import isqrt
%o A162362 from sympy import npartitions
%o A162362 def A162362(n): return n*(npartitions(n)-n)-((s:=isqrt(n))**2*(s+1)-sum((q:=n//k)*((k<<1)+q+1) for k in range(1,s+1))>>1) # _Chai Wah Wu_, Oct 22 2023
%Y A162362 Cf. A004125, A066186.
%K A162362 nonn
%O A162362 1,2
%A A162362 _Juri-Stepan Gerasimov_, Jul 02 2009
%E A162362 Entries checked by _R. J. Mathar_, May 21 2010