

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.


2



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, 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, 22, 1, 22, 23, 23, 1, 24, 24, 25, 1, 25, 26, 26, 1, 27, 27, 28, 1, 28
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OFFSET

0,4


COMMENTS

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.


LINKS



MATHEMATICA

{3#+1, 1, 3#+1, 3#+2, 3#+2, 1, 3#+3, 3#+3}& /@ Range[0, 9] // Flatten (* JeanFrançois Alcover, Nov 24 2018, from Python *)


PROG

(Python)
l=list()
for a in range(10):
l+=[3*a+1, 1, 3*a+1, 3*a+2, 3*a+2, 1, 3*a+3, 3*a+3]
(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


CROSSREFS

Exhibits a property shared with multiples of A000931.


KEYWORD

nonn,easy


AUTHOR



STATUS

approved



