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A107039 First differences of indices of squarefree Jacobsthal numbers. 2
1, 1, 1, 1, 1, 1, 1, 2, 1, 1, 1, 1, 1, 1, 1, 2, 2, 1, 1, 1, 1, 1, 2, 1, 1, 1, 1, 1, 1, 1, 2, 1, 1, 2, 2, 1, 2, 1, 1, 1, 1, 1, 1, 1, 3, 1, 1, 1, 2, 1, 2, 1, 1, 1, 1, 1, 1, 1, 2, 1, 1, 1, 1, 1, 1, 3, 1, 2, 1, 1, 1, 1, 2, 1, 1, 1, 1, 1, 1, 1, 3, 1, 1, 1, 1, 1, 1, 2, 2, 1, 1, 1, 1, 1, 2, 1, 2, 1, 1, 1, 1, 2, 1, 1, 1 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,8

COMMENTS

First differences of A107037.

LINKS

Table of n, a(n) for n=0..104.

MAPLE

A001045 := proc(n) option remember : if n <= 1 then n; else A001045(n-1)+2*A001045(n-2) ; fi ; end: A107037 := proc(nmax) local a, n; a := [] ; n := 1: while nops(a) < nmax do if numtheory[issqrfree]( A001045(n) ) then a := [op(a), n] ; fi ; n := n+1: od : RETURN(a) ; end: A107039 := proc(nmax) local a107037 ; a107037 := A107037(nmax+1) : [seq( a107037[i]-a107037[i-1], i=2..nmax)] ; end: op(A107039(120)) ; # R. J. Mathar, Aug 12 2007

CROSSREFS

Cf. A001045.

Sequence in context: A124778 A037831 A188169 * A249771 A030615 A147753

Adjacent sequences:  A107036 A107037 A107038 * A107040 A107041 A107042

KEYWORD

nonn

AUTHOR

Paul Barry, May 09 2005

EXTENSIONS

More terms from R. J. Mathar, Aug 12 2007

STATUS

approved

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Last modified March 19 23:02 EDT 2019. Contains 321343 sequences. (Running on oeis4.)