

A085349


Ratiodetermined insertion sequence I(0.26688) (see the link below).


2



1, 4, 15, 71, 269, 1274, 4827, 22861, 86617, 410224, 1554279, 7361171, 27890405, 132090854, 500473011, 2370274201, 8980623793, 42532844764, 161150755263, 763220931551, 2891732970941, 13695443923154, 51890042721675
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OFFSET

1,2


COMMENTS

This is one of the "twin" ratiodetermined insertion sequences (RDIS) that are "children" in the next generation below the "parent" sequences I(0.25024) (A004253) and I(0.26816) (A001353) in the recurrence tree of RDIS sequences. The RDIS twin of this sequence is A085348. See the link for an explanation of RDIS twin. See A082630 or A082981 for other recent examples of RDIS sequences.


LINKS



FORMULA

It appears that a(n)=18a(n2)a(n4).
Apparently a(n)a(n+3) = 11 + a(n+1)a(n+2).  Ralf Stephan, May 29 2004


MATHEMATICA

LinearRecurrence[{0, 18, 0, 1}, {1, 4, 15, 71}, 30] (* Harvey P. Dale, Mar 04 2013 *)


CROSSREFS



KEYWORD

nonn


AUTHOR



STATUS

approved



