A143677 ( 1, 2, 3, 2^2, 5, 2*3, 7, 2^3, 3^2, 2*5, 11, 2^2*3, 13,..) becomes (abs (1-2, 3-2, 2-5, 2-3, 7-2, 3-3, 2-2, 5-11, 2-2, 3-13,..)).

1, 1, 3, 1, 5, 0, 0, 6, 0, 10, 5, 2, 2, 15, 1, 17, 3, 4, 9, 21, 0, 3, 11, 0, 0, 22, 1, 26, 3, 8, 15, 2, 0, 1, 35, 16, 11, 2, 39, 4, 41, 9, 1, 3, 24, 2, 4, 0, 3, 14, 0, 40, 1, 2, 9, 4, 16, 27, 57, 1, 56, 29, 1, 5, 1, 11, 8, 65, 15, 20, 3, 64, 1, 1, 71, 34, 3, 0, 12, 9, 10, 77, 1, 1, 39, 81, 1, 2, 15

Offset

1,3

Links

Table of n, a(n) for n=1..89.

Example

Abs(1-2)=abs(-1)=1=a(1).
Abs(3-2)=abs(1)=1=a(2).
Abs(2-5)=abs(-3)=3=a(3).
Abs(2-3)=abs(-1)=1=a(4).
Abs(7-2)=abs(5)=5=a(5).
Abs(3-3)=abs(0)=0=a(6).
Abs(2-2)=abs(0)=0=a(7).
Abs(5-11)=abs(-6)=6=a(8).
Abs(2-2)=abs(0)=0=a(9).
Abs(3-13)=abs(-10)=10=a(10), 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)-3 by 2 do printf("%d, ", abs(op(n, pL)-op(n+1, pL)) ) ; od: # R. J. Mathar, Nov 06 2008

Crossrefs

Cf. A141257, A141261.

Sequence in context: A125846 A318382 A340190 * A249150 A143467 A143315

Adjacent sequences: A143674 A143675 A143676 * A143678 A143679 A143680

Keyword

nonn,less

Author

Juri-Stepan Gerasimov, Nov 01 2008

Extensions

Removed incompatibilities with internal OEIS format, extended, R. J. Mathar, Nov 06 2008

Status

approved