A054790 Earliest sequence with a(a(n))=10n.

0, 2, 10, 4, 30, 6, 50, 8, 70, 11, 20, 90, 13, 120, 15, 140, 17, 160, 19, 180, 100, 22, 210, 24, 230, 26, 250, 28, 270, 31, 40, 290, 33, 320, 35, 340, 37, 360, 39, 380, 300, 42, 410, 44, 430, 46, 450, 48, 470, 51, 60, 490, 53, 520, 55, 540, 57, 560, 59, 580, 500, 62, 610

Offset

0,2

Links

Table of n, a(n) for n=0..62.

Index entries for sequences of the a(a(n)) = 2n family

Mathematica

a[0] = 0; a[n_] := Which[m = Mod[n, 20]; m == 0, 10*n-100, m == 9, n+2, m == 10, n+10, m == 11, 10*n-20, MemberQ[ {2, 4, 6, 8, 13, 15, 17, 19}, m], 10*n-10, True, n+1]; Table[ a[n], {n, 0, 62}] (* Jean-François Alcover, Sep 24 2012 *)

Crossrefs

Cf. A002516, A002517, A002518, A007379.

Sequence in context: A199832 A189878 A189869 * A140393 A000170 A038216

Adjacent sequences: A054787 A054788 A054789 * A054791 A054792 A054793

Keyword

nice,nonn

Author

Henry Bottomley, Apr 27 2000

Status

approved