The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A130158 Table read by rows in which row n lists the positive divisors of A130157(n). 2
 1, 1, 1, 2, 1, 3, 1, 3, 1, 5, 1, 2, 4, 1, 7, 1, 2, 3, 6, 1, 3, 9, 1, 3, 9, 1, 11, 1, 3, 9, 1, 2, 5, 10, 1, 2, 7, 14, 1, 13, 1, 2, 4, 8, 16, 1, 11, 1, 2, 3, 4, 6, 12, 1, 7, 1, 2, 4, 5, 10, 20, 1, 2, 7, 14, 1, 3, 5, 15, 1, 23, 1, 2, 4, 8, 16, 1, 17, 1, 2, 13, 26 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,4 LINKS EXAMPLE Triangle starts: 1; 1; 1, 2; 1, 3; 1, 3; 1, 5; 1, 2, 4; 1, 7; 1, 2, 3, 6; ... MAPLE A130158 := proc(nmax) local a130157, a, n, anext, i ; a130157 := [1] ; a := [] ; while nops(a) < nmax do n := nops(a130157)+1 ; a := [op(a), op(numtheory[divisors](op(-1, a130157)))] ; anext :=0 ; for i from 1 to nops(a130157) do if gcd(op(i, a130157), op(n-1, a)) = 1 then anext := anext+1 ; fi ; od ; a130157 := [op(a130157), anext] ; od ; RETURN(a) ; end: A130158(80) ; # R. J. Mathar, Jun 12 2007 CROSSREFS Cf. A130157. Sequence in context: A029227 A029214 A134460 * A187497 A325704 A104984 Adjacent sequences:  A130155 A130156 A130157 * A130159 A130160 A130161 KEYWORD nonn,tabf AUTHOR Leroy Quet, May 13 2007 EXTENSIONS More terms from R. J. Mathar, Jun 12 2007 Edited by Charles R Greathouse IV, Apr 30 2010 Edited by N. J. A. Sloane, May 09 2010 STATUS approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified May 26 18:08 EDT 2020. Contains 334630 sequences. (Running on oeis4.)