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A157769
8984250n - 6468330.
3
2515920, 11500170, 20484420, 29468670, 38452920, 47437170, 56421420, 65405670, 74389920, 83374170, 92358420, 101342670, 110326920, 119311170, 128295420, 137279670, 146263920, 155248170, 164232420, 173216670, 182200920, 191185170
OFFSET
1,1
COMMENTS
The identity (1482401250*n^2-2134548900*n+768398401)^2-(27225*n^2-39202*n+14112) *(8984250*n-6468330)^2=1 can be written as A157770(n)^2-A157768(n)*a(n)^2=1.
FORMULA
a(n) = 2*a(n-1) -a(n-2).
G.f: x*(2515920+6468330*x)/(x-1)^2.
MATHEMATICA
Table[8984250*n-6468330, {n, 30}]
PROG
(Magma) I:=[2515920, 11500170]; [n le 2 select I[n] else 2*Self(n-1)-Self(n-2): n in [1..30]];
(PARI) a(n) = 8984250*n-6468330.
CROSSREFS
Sequence in context: A179733 A234910 A233927 * A183651 A259628 A251857
KEYWORD
nonn,easy
AUTHOR
Vincenzo Librandi, Mar 06 2009
STATUS
approved