login
The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A054789 Earliest sequence with a(a(n)) = 9n. 0
0, 2, 9, 4, 27, 6, 45, 8, 63, 18, 11, 90, 13, 108, 15, 126, 17, 144, 81, 20, 171, 22, 189, 24, 207, 26, 225, 36, 29, 252, 31, 270, 33, 288, 35, 306, 243, 38, 333, 40, 351, 42, 369, 44, 387, 54, 47, 414, 49, 432, 51, 450, 53, 468, 405, 56, 495, 58, 513, 60, 531, 62, 549 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

LINKS

Table of n, a(n) for n=0..62.

Index entries for sequences of the a(a(n)) = 2n family

MATHEMATICA

a[0] = 0; a[n_] := Which[m = Mod[n, 18]; m == 0, 9*n-81, m == 9, n+9, MemberQ[ {1, 3, 5, 7, 10, 12, 14, 16}, m], n+1, True, 9*n-9]; Table[ a[n], {n, 0, 62}] (* Jean-François Alcover, Sep 24 2012 *)

CROSSREFS

Cf. A002516, A002517, A002518, A007379, A008585.

Sequence in context: A171560 A302451 A220416 * A002508 A249596 A038215

Adjacent sequences:  A054786 A054787 A054788 * A054790 A054791 A054792

KEYWORD

nice,nonn

AUTHOR

Henry Bottomley, Apr 27 2000

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
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified September 23 12:43 EDT 2021. Contains 347617 sequences. (Running on oeis4.)