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 A321341 An unbounded sequence which is 1 infinitely often, with the property that for any four consecutive terms the maximum term is the sum of the two minimum terms. 0

%I

%S 1,1,1,2,2,1,3,3,4,1,4,5,5,1,6,6,7,1,7,8,8,1,9,9,10,1,10,11,11,1,12,

%T 12,13,1,13,14,14,1,15,15,16,1,16,17,17,1,18,18,19,1,19,20,20,1,21,21,

%U 22,1,22,23,23,1,24,24,25,1,25,26,26,1,27,27,28,1,28

%N An unbounded sequence which is 1 infinitely often, with the property that for any four consecutive terms the maximum term is the sum of the two minimum terms.

%C This sequence was constructed to show that there are many sequences, besides those merging with multiples of the Padovan sequence A000931, with the property that for any four consecutive terms the maximum term is the sum of the two minimum terms. This refutes a conjecture that was formerly in that entry.

%t {3#+1, 1, 3#+1, 3#+2, 3#+2, 1, 3#+3, 3#+3}& /@ Range[0, 9] // Flatten (* _Jean-François Alcover_, Nov 24 2018, from Python *)

%o (Python)

%o l=list()

%o for a in range(10):

%o l+=[3*a+1,1,3*a+1,3*a+2,3*a+2,1,3*a+3,3*a+3]

%o (PARI) a(n)={my(t=n\8*3); [t+1, 1, t+1, t+2, t+2, 1, t+3, t+3][n%8 + 1]} \\ _Andrew Howroyd_, Nov 19 2018

%Y Exhibits a property shared with multiples of A000931.

%K nonn,easy

%O 0,4

%A _David Nacin_, Nov 05 2018

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Last modified October 16 20:23 EDT 2019. Contains 328103 sequences. (Running on oeis4.)