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

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A126091 a(1)=1;a(2)=4; for n>2, a(n)=a(n-2)+3 if n is already in the sequence, a(n)=a(n-2)+1 otherwise. 0
1, 4, 2, 7, 3, 8, 6, 11, 7, 12, 10, 15, 11, 16, 14, 19, 15, 20, 18, 23, 19, 24, 22, 27, 23, 28, 26, 31, 27, 32, 30, 35, 31, 36, 34, 39, 35, 40, 38, 43, 39, 44, 42, 47, 43, 48, 46, 51, 47, 52, 50, 55, 51, 56, 54, 59, 55, 60, 58, 63, 59, 64, 62, 67, 63, 68, 66, 71, 67, 72, 70, 75 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

LINKS

Table of n, a(n) for n=1..72.

MATHEMATICA

a={1, 4}; Do[If[MemberQ[a, n], b=a[[n-2]]+3, b=a[[n-2]]+1]; AppendTo[a, b], {n, 3, 70}]; a

CROSSREFS

Cf. A080578, A080455-A080458.

Sequence in context: A222622 A161179 A105727 * A026189 A026213 A225126

Adjacent sequences:  A126088 A126089 A126090 * A126092 A126093 A126094

KEYWORD

nonn

AUTHOR

Zak Seidov, Mar 11 2007

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 19 02:36 EST 2018. Contains 317332 sequences. (Running on oeis4.)