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A272638 a(1)=1, a(2)=4; thereafter a(n) = squarefree part of a(n-1)+a(n-2). 3
1, 4, 5, 1, 6, 7, 13, 5, 2, 7, 1, 2, 3, 5, 2, 7, 1, 2, 3, 5, 2, 7, 1, 2, 3, 5, 2, 7, 1, 2, 3, 5, 2, 7, 1, 2, 3, 5, 2, 7, 1, 2, 3, 5, 2, 7, 1, 2, 3, 5, 2, 7, 1, 2, 3, 5, 2, 7, 1, 2, 3, 5, 2, 7, 1, 2, 3, 5, 2, 7, 1, 2, 3, 5, 2, 7, 1, 2, 3, 5, 2, 7, 1, 2, 3, 5, 2, 7 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,2
LINKS
MAPLE
sqrf:= n-> mul(i[1]^irem(i[2], 2), i=ifactors(n)[2]):
f:=proc(n) global sqrf; option remember;
if n = 1 then 1 elif n=2 then 4 else sqrf(f(n-1)+f(n-2)); fi; end;
[seq(f(n), n=1..140)];
CROSSREFS
Rapidly merges with A272636.
Sequence in context: A336885 A094642 A069284 * A365464 A299630 A068447
KEYWORD
nonn
AUTHOR
N. J. A. Sloane, May 05 2016
STATUS
approved

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Last modified March 28 14:21 EDT 2024. Contains 371254 sequences. (Running on oeis4.)