A077410 Combined Diophantine Chebyshev sequences A077249 and A077251.
1, 2, 12, 21, 119, 208, 1178, 2059, 11661, 20382, 115432, 201761, 1142659, 1997228, 11311158, 19770519, 111968921, 195707962, 1108378052, 1937309101, 10971811599, 19177383048, 108609737938
Offset: 0
Examples
24*a(2)^2 + 25 = 24*12^2 + 25 = 3481 = 59^2 = A077411(2)^2.
Links
- G. C. Greubel, Table of n, a(n) for n = 0..1000
- Index entries for sequences related to Chebyshev polynomials.
- Index entries for linear recurrences with constant coefficients, signature (0,10,0,-1).
Programs
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Magma
I:=[1,2,12,21]; [n le 4 select I[n] else 10*Self(n-2) - Self(n-4): n in [1..30]]; // G. C. Greubel, Jan 18 2018
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Mathematica
CoefficientList[Series[(1+x)*(1+x+x^2)/(1-10*x^2+x^4), {x,0,50}], x] (* or *) LinearRecurrence[{0,10,0,-1}, {1,2,12,21}, 30] (* G. C. Greubel, Jan 18 2018 *) -
PARI
x='x+O('x^30); Vec((1+x)*(1+x+x^2)/(1-10*x^2+x^4)) \\ G. C. Greubel, Jan 18 2018
Comments