function p = padovan ( n ) %*****************************************************************************80 % %% PADOVAN returns the first N values of the Padovan sequence. % % Discussion: % % The Padovan sequence has the initial values: % % P(0) = 1 % P(1) = 1 % P(2) = 1 % % and subsequent entries are generated by the recurrence % % P(I+1) = P(I-1) + P(I-2) % % Example: % % 0 1 % 1 1 % 2 1 % 3 2 % 4 2 % 5 3 % 6 4 % 7 5 % 8 7 % 9 9 % 10 12 % % Licensing: % % This code is distributed under the GNU LGPL license. % % Modified: % % 15 August 2004 % % Author: % % John Burkardt % % Reference: % % Ian Stewart, % "A Neglected Number", % Scientific American, Volume 274, pages 102-102, June 1996. % % Ian Stewart, % Math Hysteria, % Oxford, 2004. % % Parameters: % % Input, integer N, the number of terms. % % Output, integer P(N), terms 0 though N-1 of the Perrin sequence. % if ( n < 1 ) p = []; return end p(1) = 1; if ( n < 2 ) return end p(2) = 1; if ( n < 3 ) return end p(3) = 1; for i = 4 : n p(i) = p(i-2) + p(i-3); end return end