A173237 Alternate k and 10k for each k.

1, 10, 2, 20, 3, 30, 4, 40, 5, 50, 6, 60, 7, 70, 8, 80, 9, 90, 10, 100, 11, 110, 12, 120, 13, 130, 14, 140, 15, 150, 16, 160, 17, 170, 18, 180, 19, 190, 20, 200, 21, 210, 22, 220, 23, 230, 24, 240, 25, 250, 26, 260, 27, 270, 28, 280, 29, 290, 30, 300, 31, 310, 32, 320, 33

Offset: 1

Author

Mark Dols, Feb 13 2010

Keywords

• nonn
• easy

Links

• Index entries for linear recurrences with constant coefficients, signature (0,2,0,-1).

Crossrefs

Cf. A008592, A101233.

Formula

G.f.: x*(1+10*x) / ( (x-1)^2*(1+x)^2 ). - R. J. Mathar, Jun 18 2014