login
This site is supported by donations to The OEIS Foundation.

 

Logo

Annual appeal: Please make a donation to keep the OEIS running! Over 6000 articles have referenced us, often saying "we discovered this result with the help of the OEIS".
Other ways to donate

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
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

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent | More pages
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy .

Last modified November 23 21:46 EST 2017. Contains 295141 sequences.