OFFSET
1,1
EXAMPLE
Abs(1-2+3)=abs(2)=2=a(1).
Abs(2-2+5)=abs(5)=5=a(2).
Abs(2-3+7)=abs(6)=6=a(3).
Abs(2-3+3)=abs(2)=2=a(4).
Abs(2-2+5)=abs(5)=5=a(5).
Abs(11-2+2)=abs(11)=11=a(6).
Abs(3-13+2)=abs(-8)=8=a(7).
Abs(7-3+5)=abs(9)=9=a(8), etc.
MAPLE
pflat2 := proc(nmax) local a, ifs, n, p, c ; a := [1] ; for n from 2 to nmax do ifs := ifactors(n)[2] ; for p in ifs do a := [op(a), op(1, p)] ; if op(2, p) > 1 then a := [op(a), op(2, p)] ; fi; od: od: a ; end:
pL := pflat2(300) : for n from 1 to nops(pL)-4 by 3 do printf("%d, ", abs(op(n, pL)-op(n+1, pL)+op(n+2, pL)) ) ; od: # R. J. Mathar, Nov 06 2008
CROSSREFS
KEYWORD
nonn
AUTHOR
Juri-Stepan Gerasimov, Nov 01 2008
EXTENSIONS
Removed incompatibilities with internal OEIS format, extended R. J. Mathar, Nov 06 2008
STATUS
approved