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A036799 a(n) = 2 + 2^(n+1)*(n-1). 15
0, 2, 10, 34, 98, 258, 642, 1538, 3586, 8194, 18434, 40962, 90114, 196610, 425986, 917506, 1966082, 4194306, 8912898, 18874370, 39845890, 83886082, 176160770, 369098754, 771751938, 1610612738, 3355443202, 6979321858, 14495514626, 30064771074, 62277025794 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

COMMENTS

This sequence is a part of a class of sequences of the type: a(n) = Sum_{i=0..n} (C^i)*(i^k). This sequence has C=2, k=1. Sequence A036800 has C=2, k=2. Suppose C>=2, k>=1 are integers. What is the general closed form for a(n)? - Ctibor O. Zizka, Feb 07 2008

Partial sums of A036289. - Vladimir Joseph Stephan Orlovsky, Jul 09 2011

a(n) is the number of swaps needed in the worst case, when successively inserting 2^(n+1) - 1 keys into an initially empty binary heap (thus creating a tree with n+1 full levels). - Rudy van Vliet, Nov 09 2015

a(n) is also the total path length of the complete binary tree of height n, with nodes at depths 0,..,n. Total path length is defined to be the sum of depths over all nodes. - F. Skerman, Jul 02 2017

REFERENCES

M. Petkovsek et al., A=B, Peters, 1996, p. 97.

LINKS

Reinhard Zumkeller, Table of n, a(n) for n = 0..1000

R. K. Guy, Catwalks, sandsteps and Pascal pyramids, J. Integer Sequences, Vol. 3 (2000), Article #00.1.6.

S. Sykora, Finite and Infinite Sums of the Power Series (k^p)(x^k), DOI 10.3247/SL1Math06.002, Section V.

Index entries for linear recurrences with constant coefficients, signature (5,-8,4).

FORMULA

a(n) = 2 * A000337(n).

a(n) = Sum_{k=1..n} k*2^k. - Benoit Cloitre, Oct 25 2002

G.f.: 2*x/((1-x)*(1-2*x)^2). - Colin Barker, Apr 30 2012

a(n) = 5*a(n-1)-8*a(n-2)+4*a(n-3) for n>2. - Wesley Ivan Hurt, Nov 12 2015

a(n) = Sum_{k=0..n} Sum_{i=0..n} k * C(k,i). - Wesley Ivan Hurt, Sep 21 2017

MAPLE

A036799:=n->2+2^(n+1)*(n-1): seq(A036799(n), n=0..40); # Wesley Ivan Hurt, Nov 12 2015

MATHEMATICA

Accumulate[Table[n*2^n, {n, 0, 60}]] (* Vladimir Joseph Stephan Orlovsky, Jul 09 2011 *)

PROG

(Haskell)

a036799 n = (n - 1) * 2 ^ (n + 1) + 2  -- Reinhard Zumkeller, May 24 2012

(PARI) a(n)=2+(n-1)<<(n+1) \\ Charles R Greathouse IV, Sep 28 2015

(PARI) concat(0, Vec(2*x/((1-x)*(1-2*x)^2) + O(x^50))) \\ Altug Alkan, Nov 09 2015

(MAGMA) [2+2^(n+1)*(n-1) : n in [0..40]]; // Wesley Ivan Hurt, Nov 12 2015

CROSSREFS

Cf. A000337, A036289, A036800, A232599, A232600, A232601, A232602.

Sequence in context: A304159 A211905 A022498 * A190161 A196969 A119193

Adjacent sequences:  A036796 A036797 A036798 * A036800 A036801 A036802

KEYWORD

nonn,easy

AUTHOR

N. J. A. Sloane

STATUS

approved

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Last modified November 18 07:22 EST 2019. Contains 329252 sequences. (Running on oeis4.)