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.

A004435 Positive integers that are not the sum of 2 distinct square integers.

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%I A004435 #21 Oct 26 2023 00:19:23
%S A004435 2,3,6,7,8,11,12,14,15,18,19,21,22,23,24,27,28,30,31,32,33,35,38,39,
%T A004435 42,43,44,46,47,48,51,54,55,56,57,59,60,62,63,66,67,69,70,71,72,75,76,
%U A004435 77,78,79,83,84,86,87,88,91
%N A004435 Positive integers that are not the sum of 2 distinct square integers.
%C A004435 A025435(a(n)) = 0. - _Reinhard Zumkeller_, Dec 20 2013
%H A004435 T. D. Noe, <a href="/A004435/b004435.txt">Table of n, a(n) for n=1..1000</a>
%H A004435 <a href="/index/Su#ssq">Index entries for sequences related to sums of squares</a>
%t A004435 Select[Range[100], Reduce[0 <= i < j && # == i^2 + j^2, {i, j}, Integers] === False &] (* _Jean-François Alcover_, Aug 01 2018 *)
%o A004435 (Haskell)
%o A004435 a004435 n = a004435_list !! (n-1)
%o A004435 a004435_list = [x | x <- [1..], a025435 x == 0]
%o A004435 -- _Reinhard Zumkeller_, Dec 20 2013
%Y A004435 Cf. A001983 (complement).
%K A004435 nonn
%O A004435 1,1
%A A004435 _N. J. A. Sloane_