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%I #30 Jun 10 2022 10:33:12
%S 4,9,16,16,25,25,36,36,36,49,49,49,64,64,64,64,81,81,81,81,100,100,
%T 100,100,100,121,121,121,121,121,144,144,144,144,144,144,169,169,169,
%U 169,169,169,196,196,196,196,196,196,196,225,225,225,225,225,225,225
%N Interleave (2*n+2)^2 with (2*n+3)^2, both listed n+1 times.
%C Discovered via Janet's sequence A167268: the result of adding to A167268 the smallest increasing sequence (2, 7, 10, 14, 19, 23, 26, 30, 34, 39, 43, 47, ...) as to get a sequence of nondecreasing squares.
%C Even terms: 4, 16, 16, 36, 36, 36, ... = 4*A093995(n+1).
%C Odd terms: (A131507(n) + 2)^2.
%H Harvey P. Dale, <a href="/A248928/b248928.txt">Table of n, a(n) for n = 0..1000</a>
%F a(n) = A027434(n+1)^2.
%e Seen as an irregular triangle:
%e 4;
%e 9;
%e 16, 16;
%e 25, 25;
%e 36, 36, 36;
%e 49, 49, 49;
%e 64, 64, 64, 64;
%e 81, 81, 81, 81;
%e ...
%t Module[{nn=10,a,b},a=Table[PadRight[{},n+1,(2n+2)^2],{n,0,nn}];b= Table[ PadRight[ {},n+1,(2n+3)^2],{n,0,nn}];Riffle[a,b]]//Flatten (* _Harvey P. Dale_, Jun 10 2022 *)
%o (PARI) vector(60, n, (sqrtint(4*n-3)+1)^2) \\ after _Charles R Greathouse IV_, _Michel Marcus_, Oct 27 2014
%Y Cf. A000267, A007395, A027434, A093995, A131507, A167268.
%K nonn,tabf
%O 0,1
%A _Paul Curtz_, Oct 17 2014
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