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a(n) = largest square k <= n such that A002828(n-k) = A002828(n)-1.
4

%I #7 Oct 04 2015 13:08:20

%S 0,1,1,1,4,4,4,4,4,9,9,9,4,9,9,9,16,16,9,9,16,16,9,9,16,25,25,25,25,

%T 25,25,25,16,25,25,25,36,36,36,36,36,25,25,25,36,36,36,36,16,49,49,49,

%U 36,49,49,49,36,49,49,49,49,36,49,49,64,64,64,49,64,64,36,49,36,64,49,49,36,64,49,49,64,81,81,81,64,81,81,81,36,64,81,81,81,64,81,81,64,81,49,81,100

%N a(n) = largest square k <= n such that A002828(n-k) = A002828(n)-1.

%H Antti Karttunen, <a href="/A262690/b262690.txt">Table of n, a(n) for n = 0..65536</a>

%H A. Karttunen, <a href="https://oeis.org/plot2a?name1=A262690&amp;name2=A048760&amp;tform1=untransformed&amp;tform2=untransformed&amp;shift=0&amp;radiop1=ratio&amp;drawlines=true">Ratio a(n)/A048760(n) drawn with the help of OEIS Plot2-script</a>

%F a(n) = A000290(A262689(n)).

%F Other identities. For all n >= 0:

%F A262678(n) = n - a(n).

%o (Scheme) (define (A262690 n) (A000290 (A262689 n)))

%Y Cf. A000290, A002828, A262689, A262678.

%Y Cf. also A048760.

%K nonn

%O 0,5

%A _Antti Karttunen_, Oct 03 2015