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 A090570 Numbers that are congruent to {0, 1} mod 9. 8
 0, 1, 9, 10, 18, 19, 27, 28, 36, 37, 45, 46, 54, 55, 63, 64, 72, 73, 81, 82, 90, 91, 99, 100, 108, 109, 117, 118, 126, 127, 135, 136, 144, 145, 153, 154, 162, 163, 171, 172, 180, 181, 189, 190, 198, 199, 207, 208, 216, 217, 225, 226 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,3 COMMENTS A145389(a(n)) = A010888(a(n)). [Reinhard Zumkeller, Oct 10 2008] LINKS Index entries for linear recurrences with constant coefficients, signature (1,1,-1). FORMULA a(n) = 9*n-a(n-1)-17 (with a(1)=0). [Vincenzo Librandi, Nov 16 2010] a(n) = 9*n/2 -25/4 -7*(-1)^n/4. G.f.: x^2*(1+8*x)/( (1+x)*(x-1)^2 ). - R. J. Mathar, Oct 08 2011 a(n+1) = Sum_k>=0 {A030308(n,k)*A005010(k-1)}, with A005010(-1)=1. - Philippe Deléham, Oct 17 2011. EXAMPLE 13 is 1101 in base 2, so a(13+1)=a(14)=36*1+18*1+9*0+1*1=36+18+1=55. - Philippe Deléham, Oct 17 2011 MAPLE a[0]:=0:a[1]:=1:for n from 2 to 100 do a[n]:=a[n-2]+9 od: seq(a[n], n=0..51); # Zerinvary Lajos, Mar 16 2008 PROG (PARI) forstep(n=0, 200, [1, 8], print1(n", ")) \\ Charles R Greathouse IV, Oct 17 2011 CROSSREFS Union of A008591 and A017173. [Reinhard Zumkeller, Oct 10 2008] Sequence in context: A217935 A100595 A107433 * A131417 A268135 A058369 Adjacent sequences:  A090567 A090568 A090569 * A090571 A090572 A090573 KEYWORD nonn,easy AUTHOR Giovanni Teofilatto, Feb 25 2004 STATUS approved

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Last modified January 22 23:00 EST 2019. Contains 319365 sequences. (Running on oeis4.)