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Row sums of triangle A132044.
7

%I #32 Feb 13 2021 03:06:22

%S 1,2,3,6,13,28,59,122,249,504,1015,2038,4085,8180,16371,32754,65521,

%T 131056,262127,524270,1048557,2097132,4194283,8388586,16777193,

%U 33554408,67108839,134217702,268435429,536870884,1073741795,2147483618,4294967265,8589934560

%N Row sums of triangle A132044.

%C Apart from initial terms, and with a change of offset, same as A095768. - _Jon E. Schoenfield_, Jun 15 2017

%H G. C. Greubel, <a href="/A132045/b132045.txt">Table of n, a(n) for n = 0..1000</a>

%H <a href="/index/Rec#order_3">Index entries for linear recurrences with constant coefficients</a>, signature (4,-5,2).

%F Binomial transform of (1, 1, 0, 2, 0, 2, 0, 2, 0, 2, ...).

%F For n>=1, a(n) = 2^n - n + 1 = A000325(n) + 1. - Avik Roy (avik_3.1416(AT)yahoo.co.in), Jan 17 2009. (Corrected by _Franklin T. Adams-Watters_, Jan 17 2009)

%F E.g.f.: U(0)- 1, where U(k) = 1 - x/(2^k + 2^k/(x - 1 - x^2*2^(k+1)/(x*2^(k+1) + (k+1)/U(k+1) ))). - _Sergei N. Gladkovskii_, Dec 01 2012

%F From _Colin Barker_, Mar 14 2014: (Start)

%F a(n) = 4*a(n-1) - 5*a(n-2) + 2*a(n-3) for n>3.

%F G.f.: (1-2*x+2*x^3) / ((1-x)^2*(1-2*x)). (End)

%e a(4) = 13 = sum of row 4 terms of triangle A132044: (1 + 3 + 5 + 3 + 1).

%e a(4) = 13 = (1, 4, 6, 4, 1) dot (1, 1, 0, 2, 0) = (1 + 4 + 0 + 8 + 0).

%t Table[2^n -(n-1) -Boole[n==0], {n, 0, 35}] (* _G. C. Greubel_, Feb 12 2021 *)

%o (PARI) Vec((1-2*x+2*x^3)/((1-x)^2*(1-2*x)) + O(x^100)) \\ _Colin Barker_, Mar 14 2014

%o (Sage) [1]+[2^n -n +1 for n in (1..35)] # _G. C. Greubel_, Feb 12 2021

%o (Magma) [1] cat [2^n -n +1: n in [1..35]]; // _G. C. Greubel_, Feb 12 2021

%Y Cf. A000325, A095768, A132044.

%K nonn,easy

%O 0,2

%A _Gary W. Adamson_, Aug 08 2007