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A022023 Define the sequence S(a(0),a(1)) by a(n+2) is the least integer such that a(n+2)/a(n+1) > a(n+1)/a(n) for n >= 0. This is S(6,30). 1
6, 30, 151, 761, 3836, 19337, 97477, 491378, 2477019, 12486565, 62944332, 317300149, 1599498817, 8063016906, 40645382751, 204891935393, 1032852992092, 5206575364849, 26246162074765, 132305973770306, 666949729466899, 3362069972805741, 16948075698414380 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,1

COMMENTS

This coincides with the linearly recurrent sequence defined by the expansion of (6 - 5*x^2)/(1 - 5*x - x^2 + 4*x^3) only up to n <= 69. - Bruno Berselli, Feb 11 2016

LINKS

Colin Barker, Table of n, a(n) for n = 0..1000

FORMULA

a(n+1) = floor(a(n)^2/a(n-1))+1 for all n > 0. - M. F. Hasler, Feb 10 2016

MAPLE

A022023 := proc(n)

    option remember;

    if n <= 1 then

        op(n+1, [6, 30]) ;

    else

        a := procname(n-1)^2/procname(n-2) ;

        if type(a, 'integer') then

            a+1 ;

        else

            ceil(a) ;

        fi;

    end if;

end proc: # R. J. Mathar, Feb 10 2016

PROG

(PARI) a=[6, 30]; for(n=2, 30, a=concat(a, a[n]^2\a[n-1]+1)); a \\ M. F. Hasler, Feb 10 2016

CROSSREFS

Cf. A022018 - A022025, A022026 - A022032.

Sequence in context: A252699 A054117 A033132 * A066534 A126474 A127017

Adjacent sequences:  A022020 A022021 A022022 * A022024 A022025 A022026

KEYWORD

nonn

AUTHOR

R. K. Guy

EXTENSIONS

Double-checked and extended to 3 lines of data by M. F. Hasler, Feb 10 2016

STATUS

approved

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Last modified September 17 16:50 EDT 2021. Contains 347487 sequences. (Running on oeis4.)