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 A061650 a(n) = n*20^(n-1). 1
 1, 40, 1200, 32000, 800000, 19200000, 448000000, 10240000000, 230400000000, 5120000000000, 112640000000000, 2457600000000000, 53248000000000000, 1146880000000000000, 24576000000000000000, 524288000000000000000, 11141120000000000000000, 235929600000000000000000 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 LINKS Harry J. Smith, Table of n, a(n) for n = 1..100 Index entries for linear recurrences with constant coefficients, signature (40,-400). FORMULA G.f.: x /(1 - 20*x)^2. - Vincenzo Librandi, Jul 02 2018 a(n) = n*20^(n-1). MATHEMATICA CoefficientList[Series[(1)/(1 - 20 x)^2, {x, 0, 20}], x] (* Vincenzo Librandi, Jul 02 2018 *) LinearRecurrence[{40, -400}, {1, 40}, 20] (* Harvey P. Dale, Aug 01 2021 *) PROG (PARI) { for (n=1, 100, write("b061650.txt", n, " ", n*20^(n - 1)) ) } \\ Harry J. Smith, Jul 25 2009 (Magma) [n*20^(n-1): n in [1..20]]; // Vincenzo Librandi, Jul 02 2018 CROSSREFS Sequence in context: A152257 A229457 A331350 * A006101 A278381 A251202 Adjacent sequences: A061647 A061648 A061649 * A061651 A061652 A061653 KEYWORD easy,nonn AUTHOR Jason Earls, Jun 14 2001 EXTENSIONS Corrected and extended by Larry Reeves (larryr(AT)acm.org), Jun 18 2001 STATUS approved

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Last modified March 25 18:33 EDT 2023. Contains 361528 sequences. (Running on oeis4.)