The OEIS mourns the passing of Jim Simons and is grateful to the Simons Foundation for its support of research in many branches of science, including the OEIS.
login
The OEIS is supported by the many generous donors to the OEIS Foundation.

 

Logo
Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A077383 a(1) = 1, then add, multiply and subtract 2, 3, 4; 5, 6, 7; ... in that order. 6
1, 3, 9, 5, 10, 60, 53, 61, 549, 539, 550, 6600, 6587, 6601, 99015, 98999, 99016, 1782288, 1782269, 1782289, 37428069, 37428047, 37428070, 898273680, 898273655, 898273681, 24253389387, 24253389359, 24253389388, 727601681640, 727601681609 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,2
LINKS
EXAMPLE
a(2) = a(1) + 2 = 3, a(3) = 3*3 = 9, a(4) = 9 - 4 = 5, a(5) = 5 + 5 = 10, etc.
MAPLE
a := proc(n) if n=1 then 1 elif n mod 3 = 2 then a(n-1)+n elif n mod 3 = 0 then n*a(n-1) elif n mod 3 = 1 then a(n-1)-n else fi end: # Emeric Deutsch, Dec 17 2003
MATHEMATICA
FoldList[If[Mod[#2, 3]==2, #1+#2, If[Mod[#2, 3]==0, #1*#2, #1-#2]]&, 1, Range[2, 31]] (* James C. McMahon, Oct 10 2023 *)
PROG
(Python)
from itertools import count, islice
def A077383_gen(): # generator of terms
yield (a:=1)
for n in count(2, 3):
yield (a:=a+n)
yield (a:=a*(n+1))
yield (a:=a-n-2)
A077383_list = list(islice(A077383_gen(), 20)) # Chai Wah Wu, Apr 19 2023
CROSSREFS
Other operation orders: A077382, A077384, A362269, A362270, A362271, A362272.
Sequence in context: A096418 A100811 A223652 * A084492 A327762 A327460
KEYWORD
nonn
AUTHOR
Amarnath Murthy, Nov 06 2002
EXTENSIONS
More terms from Emeric Deutsch, Dec 17 2003
STATUS
approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recents
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified May 19 20:45 EDT 2024. Contains 372703 sequences. (Running on oeis4.)