A076603 a(1)=9, a(n_even)=(a(n-1)^2-1)/2; a(n_odd)=a(n-1)+1.

9, 40, 41, 840, 841, 353640, 353641, 62530978440, 62530978441, 1955061632394403395240, 1955061632394403395241, 1911132993230334657643987512400814230724040, 1911132993230334657643987512400814230724041

Offset: 1

Author

Zak Seidov, Oct 21 2002

Keywords

• easy
• nonn

Comments

{9, 40, 41}, {41, 840, 841}, {841, 353640, 353641}... are sides {a

Programs

Mathematica

nxt[{n_,a_}]:={n+1,If[EvenQ[n+1],(a^2-1)/2,a+1]}; Transpose[ NestList[ nxt,{1,9},10]][[2]] (* Harvey P. Dale, Oct 15 2012 *)

Extensions

More terms from Harvey P. Dale, Oct 15 2012

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