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A157735
18522n - 8274.
3
10248, 28770, 47292, 65814, 84336, 102858, 121380, 139902, 158424, 176946, 195468, 213990, 232512, 251034, 269556, 288078, 306600, 325122, 343644, 362166, 380688, 399210, 417732, 436254, 454776, 473298, 491820, 510342, 528864, 547386
OFFSET
1,1
COMMENTS
The identity (388962*n^2-347508*n+77617)^2-(441*n^2-394*n+88)*(18522*n- 8274)^2=1 can be written as A157736(n)^2-A157734(n)*a(n)^2=1.
FORMULA
a(n) = 2*a(n-1) - a(n-2).
G.f.: x*(10248+8274*x)/(x-1)^2.
MATHEMATICA
LinearRecurrence[{2, -1}, {10248, 28770}, 40]
PROG
(Magma) I:=[10248, 28770]; [n le 2 select I[n] else 2*Self(n-1)-Self(n-2): n in [1..40]];
(PARI) a(n) = 18522*n - 8274.
CROSSREFS
Sequence in context: A156119 A109176 A187796 * A332532 A252031 A356979
KEYWORD
nonn,easy
AUTHOR
Vincenzo Librandi, Mar 05 2009
STATUS
approved