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 A086192 Tribonacci numbers that start with first three squares. 2
 1, 4, 9, 14, 27, 50, 91, 168, 309, 568, 1045, 1922, 3535, 6502, 11959, 21996, 40457, 74412, 136865, 251734, 463011, 851610, 1566355, 2880976, 5298941, 9746272, 17926189, 32971402, 60643863, 111541454, 205156719, 377342036, 694040209 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 COMMENTS n and a(n) are of the same parity. Except for the first three terms and a(5)=27, there is no perfect powers (A001597) in the first 225 terms. In fact there is always at least one factor which is represented only once. - Robert G. Wilson v, Aug 27 2003 LINKS Martin Burtscher, Igor Szczyrba, Rafał Szczyrba, Analytic Representations of the n-anacci Constants and Generalizations Thereof, Journal of Integer Sequences, Vol. 18 (2015), Article 15.4.5. Index entries for linear recurrences with constant coefficients, signature (1,1,1). FORMULA a(n) = a(n-1) + a(n-2) + a(n-3). a(n) = 4*A000073(n)+3*A000073(n-1)+A000073(n-2). G.f.: -x*(1+3*x+4*x^2)/(-1+x+x^2+x^3). [From R. J. Mathar, Apr 20 2009] MATHEMATICA a = 1; a = 4; a = 9; a[n_] := a[n] = a[n - 3] + a[n - 2] + a[n - 1]; Table[ a[n], {n, 1, 30}] Transpose[NestList[Flatten[{Rest[#], Total[#]}]&, {1, 4, 9}, 40]][] (* Harvey P. Dale, Mar 24 2011 *) LinearRecurrence[{1, 1, 1}, {1, 4, 9}, 33] (* Ray Chandler, Dec 08 2013 *) CROSSREFS Cf. A000213. Sequence in context: A004630 A073497 A244941 * A105503 A095169 A345407 Adjacent sequences:  A086189 A086190 A086191 * A086193 A086194 A086195 KEYWORD nonn,easy AUTHOR Jun Mizuki (suzuki32(AT)sanken.osaka-u.ac.jp), Aug 26 2003 EXTENSIONS More terms from Robert G. Wilson v, Aug 27 2003 STATUS approved

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Last modified October 1 09:13 EDT 2022. Contains 357140 sequences. (Running on oeis4.)