A127207 Half-indexed Lucas numbers a(n)=round(sqrt((1+sqrt(5))/2)^n) a(2n)=L(n)=A000032, so a(n)=L(n/2).

1, 2, 2, 3, 3, 4, 5, 7, 9, 11, 14, 18, 23, 29, 37, 47, 60, 76, 97, 123, 156, 199, 253, 322, 410, 521, 663, 843, 1072, 1364, 1735, 2207, 2807, 3571, 4542, 5778, 7350, 9349, 11892, 15127, 19242, 24476, 31134, 39603, 50376, 64079

Offset

1,2

Comments

a(n)+a(n+2)=a(n+4), a(n+4)+1 or a(n+4)-1.

Links

Table of n, a(n) for n=1..46.

Maple

for n from 1 to 60 do a[n]:=round(sqrt((1+sqrt(5))/2)^n) od: seq(a[n], n=1..60);

Crossrefs

Cf. A000032.

Sequence in context: A367399 A113788 A018243 * A173513 A367693 A147663

Adjacent sequences: A127204 A127205 A127206 * A127208 A127209 A127210

Keyword

easy,nonn

Author

Miklos Kristof, Mar 28 2007

Status

approved