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A027958 a(n) = T(n,m) + T(n,m+1) + ... + T(n,n), where m = floor((n+2)/2), T given by A027948. 1
1, 1, 4, 5, 20, 32, 95, 169, 424, 793, 1816, 3488, 7583, 14789, 31172, 61357, 126892, 251200, 513343, 1019921, 2068496, 4119281, 8313584, 16580800, 33358015, 66594637, 133703500, 267089189, 535524644, 1070217248, 2143959071 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,3

COMMENTS

a(n) is the sum of the terms of the 2nd half of the n-th row of the A027948 triangle. - Michel Marcus, Oct 01 2019

LINKS

G. C. Greubel, Table of n, a(n) for n = 1..1000

Index entries for linear recurrences with constant coefficients, signature (2,4,-8,-4,8,1,-2).

FORMULA

G.f.: x*(1 -x -2*x^2 + x^3 +6*x^4 -2*x^6)/((1-2*x)*(1-x^2)(1+x-x^2)*(1-x-x^2)).

a(n) = (3 +(-1)^n +2^(n+1) -(-1)^n*Fibonacci(n+1) -Fibonacci(n+4))/2. - G. C. Greubel, Sep 30 2019

MAPLE

f:= combinat[fibonacci]: seq((3 +(-1)^n +2^(n+1) -(-1)^n*f(n+1) -f(n+4))/2, n=1..40); # G. C. Greubel, Sep 30 2019

MATHEMATICA

Table[(3 +(-1)^n +2^(n+1) -(-1)^n*Fibonacci[n+1] -Fibonacci[n+4])/2, {n, 40}] (* G. C. Greubel, Sep 30 2019 *)

PROG

(PARI) vector(40, n, f=fibonacci; (3 +(-1)^n +2^(n+1) -(-1)^n*f(n+1) -f(n+4))/2 ) \\ G. C. Greubel, Sep 30 2019

(MAGMA) F:=Fibonacci; [(3 +(-1)^n +2^(n+1) -(-1)^n*F(n+1) -F(n+4))/2: n in [1..40]]; // G. C. Greubel, Sep 30 2019

(Sage) f=fibonacci; [(3 +(-1)^n +2^(n+1) -(-1)^n*f(n+1) -f(n+4))/2 for n in (1..40)] # G. C. Greubel, Sep 30 2019

(GAP) F:=Fibonacci;; List([1..40], n-> (3 +(-1)^n +2^(n+1) -(-1)^n*F(n+1) -F(n+4))/2); # G. C. Greubel, Sep 30 2019

CROSSREFS

Cf. A000045, A027948.

Sequence in context: A182584 A240860 A059182 * A293942 A064670 A119283

Adjacent sequences:  A027955 A027956 A027957 * A027959 A027960 A027961

KEYWORD

nonn

AUTHOR

Clark Kimberling

STATUS

approved

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Last modified June 2 14:04 EDT 2020. Contains 334781 sequences. (Running on oeis4.)