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 A171475 a(n) = 6*a(n-1)-8*a(n-2) for n > 2; a(0) = 1, a(1) = 6, a(2) = 27. 1
 1, 6, 27, 114, 468, 1896, 7632, 30624, 122688, 491136, 1965312, 7862784, 31454208, 125822976, 503304192, 2013241344, 8053014528, 32212156416, 128848822272, 515395682304, 2061583515648, 8246335635456, 32985345687552 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,2 COMMENTS Binomial transform of A037480; second binomial transform of A133600. First differences of A080960. LINKS Vincenzo Librandi, Table of n, a(n) for n = 0..500 FORMULA a(n) = 3*(5*4^n-2*2^n)/8 for n > 0. G.f.: (1-x)*(1+x)/((1-2*x)*(1-4*x)). PROG (PARI) {m=21; v=concat([1, 6, 27], vector(m-3)); for(n=4, m, v[n]=6*v[n-1]-8*v[n-2]); v} CROSSREFS Cf. A037480 ((5*3^n+(-1)^n-6)/8), A133600 (row sums of triangle A133599), A080960 (third binomial transform of A010685). Sequence in context: A176476 A079742 A291232 * A130019 A196919 A049651 Adjacent sequences:  A171472 A171473 A171474 * A171476 A171477 A171478 KEYWORD nonn,easy AUTHOR Klaus Brockhaus, Dec 09 2009 STATUS approved

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Last modified September 17 16:32 EDT 2021. Contains 347487 sequences. (Running on oeis4.)