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A111104
Difference between successive terms of A051484.
1
2, 1, 4, 6, 6, 6, 18, 18, 48, 30, 12, 30, 6, 42, 66, 42, 150, 18, 12, 48, 6, 72, 12, 30, 138, 60, 18, 84, 204, 54, 36, 6, 144, 12, 156, 24, 18, 60, 36, 6, 126, 48, 18, 168, 42, 12, 12, 204, 78, 6, 6, 18, 54, 84, 30, 24, 18, 150, 72, 6, 6, 36, 42, 66, 126, 318, 186, 18, 24, 54
OFFSET
1,1
COMMENTS
All elements of A051484 from the fourth element, 7, onward are either 1 or 7 modulo 12. Each difference between successive terms of A051484 from the fourth term, 7, onward are equal to 0 or 6 modulo 12.
FORMULA
a(n) = A051484(n+1)-A051484(n), n>=1.
EXAMPLE
a(8)=A051484(8)-A051484(7)=43-25=18.
MAPLE
M:=[0, 2]: isElement := proc(n) global M; local b, j, k; b:=true; for j from 1 to nops(M)-1 do for k from j+1 to nops(M) do if M[j] = n mod M[k] then b:=false; break; fi od od; return b end: for z to 1 do for n from 3 to 1000 do if isElement(n) then M:=[op(M), n] fi od od; M; map(proc(k) M[k]-M[k-1] end, [$2..nops(M)]);
MATHEMATICA
a[1] = 0; a[2] = 2; a[n_] := a[n] = Block[{k = a[n - 1] + 1, t = a[ # ] & /@ Range[n - 1]}, While[ Intersection[t, Union[ Mod[k, Rest[ t]]]] != {}, k++ ]; k]; t = Table[ a[n], {n, 71}]; Drop[t, 1] - Drop[t, -1] (* Robert G. Wilson v *)
CROSSREFS
Cf. A051484.
Sequence in context: A131452 A359898 A335920 * A026190 A262599 A160016
KEYWORD
nonn
AUTHOR
Walter Kehowski, Oct 14 2005
EXTENSIONS
More terms from Robert G. Wilson v, Oct 19 2005
STATUS
approved