login
A059417
Start with 1; square; add 2; subtract 1; repeat.
1
1, 1, 3, 2, 4, 6, 5, 25, 27, 26, 676, 678, 677, 458329, 458331, 458330, 210066388900, 210066388902, 210066388901, 44127887745906175987801, 44127887745906175987803, 44127887745906175987802
OFFSET
0,3
COMMENTS
a(22) has 46 digits.
REFERENCES
Seen on a quiz.
LINKS
FORMULA
a(1+3k) = A004019(k+1), a(2+3k) = A004019(k+1)+2, a(3+3k) = A004019(k+1)+1, k>=0. - Yuriy Sibirmovsky, Sep 04 2016
MATHEMATICA
Flatten@ NestList[# + {0, 2, 1} &[Last[#]^2] &, {1}, 7] (* Michael De Vlieger, Sep 06 2016 *)
PROG
(PARI) { for (n = 0, 36, if (n==0, a=1, if (n%3 == 1, a*=a, if (n%3==2, a+=2, if (n%3==0, a-=1)))); write("b059417.txt", n, " ", a); ) } \\ Harry J. Smith, Jun 26 2009
CROSSREFS
Cf. A004019.
Sequence in context: A126290 A277377 A227741 * A078824 A014685 A239516
KEYWORD
easy,nonn
AUTHOR
Jonathan Scharff (jonscharff(AT)home.com), Jan 30 2001
EXTENSIONS
More terms from Larry Reeves (larryr(AT)acm.org), Jan 31 2001
STATUS
approved