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

 

Logo

Annual Appeal: Please make a donation to keep the OEIS running. In 2018 we replaced the server with a faster one, added 20000 new sequences, and reached 7000 citations (often saying "discovered thanks to the OEIS").
Other ways to donate

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A118551 a(0)=1. a(n) = a(n-1)*2, if n is in the sequence. a(n) = a(n-1) + 1 if n is missing from the sequence. 12
1, 2, 4, 5, 10, 20, 21, 22, 23, 24, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 114, 228, 456, 912, 1824, 1825, 1826, 1827, 1828, 1829, 1830, 1831, 1832, 1833, 1834, 1835, 1836, 1837, 1838, 1839, 1840, 1841, 1842, 1843, 1844, 1845, 1846, 1847, 3694, 7388, 14776 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

LINKS

Table of n, a(n) for n=0..50.

MATHEMATICA

f[s_] := Block[{n = Length@s}, Append[s, If[ MemberQ[s, n], 2s[[ -1]], s[[ -1]] + 1]]]; Nest[f, {1}, 50] - Robert G. Wilson v, May 16 2006

CROSSREFS

Sequence in context: A000675 A005018 A249399 * A161706 A128401 A018467

Adjacent sequences:  A118548 A118549 A118550 * A118552 A118553 A118554

KEYWORD

easy,nonn

AUTHOR

Leroy Quet, May 03 2006

EXTENSIONS

More terms from Robert G. Wilson v, May 16 2006

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 December 17 14:50 EST 2018. Contains 318201 sequences. (Running on oeis4.)