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A104863 "Floor of hypotenuse": a(n)=floor[sqrt[a(n-1)^2+a(n-2)^2]], a(1)=10, a(2)=30. Cf. A104803. 3
10, 30, 31, 43, 53, 68, 86, 109, 138, 175, 222, 282, 358, 455, 578, 735, 935, 1189, 1512, 1923, 2446, 3111, 3957, 5033, 6402, 8143, 10358, 13175, 16759, 21317, 27116, 34491 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Harvey P. Dale, Table of n, a(n) for n = 1..1000

FORMULA

For n>=17, a(n) = a(n-2)+a(n-4)+1 (conjectured). If true then for m>5, a(2m+1) = 4Fib(m)+25Fib(m+1)+1 and a(2m+2) = 8Fib(m)+30Fib(m+1)+1 with Fib(n)=A000045(n). -- Ralf Stephan, Nov 15 2010.

MATHEMATICA

nxt[{a_, b_}]:={b, Floor[Sqrt[a^2+b^2]]}; Transpose[NestList[nxt, {10, 30}, 40]][[1]] (* Harvey P. Dale, Jun 18 2013 *)

CROSSREFS

Cf. A104803, A104804, A104805, A104806, A104864.

Sequence in context: A002422 A031195 A034117 * A027183 A096844 A031299

Adjacent sequences:  A104860 A104861 A104862 * A104864 A104865 A104866

KEYWORD

nonn

AUTHOR

Zak Seidov, Mar 28 2005

STATUS

approved

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Last modified May 24 09:22 EDT 2017. Contains 286963 sequences.