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A176634
a(n) = 6*a(n-1)-8*a(n-2)-3 for n > 2; a(0) = 89, a(1) = 519, a(2) = 2063.
5
89, 519, 2063, 8223, 32831, 131199, 524543, 2097663, 8389631, 33556479, 134221823, 536879103, 2147500031, 8589967359, 34359803903, 137439084543, 549756076031, 2199023779839, 8796094070783, 35184374185983
OFFSET
0,1
COMMENTS
Related to Reverse and Add trajectory of 77 in base 2: a(n)= A075253(4*n+2)/3, i.e., one third of third quadrisection of A075253.
FORMULA
a(n) = 128*4^n+4*2^n-1 for n > 0, a(1) = 89.
G.f.: (89-104*x-324*x^2+336*x^3)/((1-x)*(1-2*x)*(1-4*x)).
G.f. for the sequence starting at a(1): x*(519-1570*x+1048*x^2)/((1-x)* (1-2*x)*(1-4*x)).
MATHEMATICA
CoefficientList[Series[(89 - 104 x - 324 x^2 + 336 x^3)/((1 - x) (1 - 2 x) (1 - 4 x)), {x, 0, 40}], x] (* Vincenzo Librandi, Sep 24 2013 *)
LinearRecurrence[{7, -14, 8}, {89, 519, 2063, 8223}, 20] (* Harvey P. Dale, Jun 20 2023 *)
PROG
(PARI) {m=20; v=concat([89, 519, 2063], vector(m-3)); for(n=4, m, v[n]=6*v[n-1]-8*v[n-2]-3); v}
(Magma) [89] cat [128*4^n+4*2^n-1: n in [1..25]]; // Vincenzo Librandi, Sep 24 2013
CROSSREFS
Cf. A075253 (Reverse and Add trajectory of 77 in base 2), A176632, A176633, A176635.
Sequence in context: A172523 A159747 A141866 * A224740 A028472 A136646
KEYWORD
nonn
AUTHOR
Klaus Brockhaus, Apr 22 2010
STATUS
approved