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A077242 Combined Diophantine Chebyshev sequences A077240 and A077239. 4
5, 7, 23, 37, 133, 215, 775, 1253, 4517, 7303, 26327, 42565, 153445, 248087, 894343, 1445957, 5212613, 8427655, 30381335, 49119973, 177075397, 286292183, 1032071047, 1668633125, 6015350885, 9725506567 (list; graph; refs; listen; history; internal format)
OFFSET

0,1

COMMENTS

a(n)^2 - 8*b(n)^2 = 17, with the companion sequence b(n)= A077241(n).

LINKS

Index entries for sequences related to Chebyshev polynomials.

FORMULA

a(2*k)= A077240(k) and a(2*k+1)= A077239(k), k>=0.

G.f.: (1-x)*(5+12*x+5*x^2)/(1-6*x^2+x^4).

EXAMPLE

23 = a(2) = sqrt(8*A077241(2)^2 + 17) = sqrt(8*8^2 + 17)= sqrt(529) = 23.

CROSSREFS

Sequence in context: A156123 A166251 A167936 * A121182 A173970 A028287

Adjacent sequences:  A077239 A077240 A077241 * A077243 A077244 A077245

KEYWORD

nonn,easy

AUTHOR

Wolfdieter Lang (wolfdieter.lang(AT)physik.uni-karlsruhe.de), Nov 08 2002

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Last modified February 17 14:50 EST 2012. Contains 206050 sequences.