A111104 Difference between successive terms of A051484.

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.

Links

Table of n, a(n) for n=1..70.

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

Adjacent sequences: A111101 A111102 A111103 * A111105 A111106 A111107

Keyword

nonn

Author

Walter Kehowski, Oct 14 2005

Extensions

More terms from Robert G. Wilson v, Oct 19 2005

Status

approved