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A133600 Row sums of triangle A133599. 3
1, 4, 7, 16, 28, 64, 112, 256, 448, 1024, 1792, 4096, 7168, 16384, 28672, 65536, 114688, 262144, 458752, 1048576, 1835008, 4194304, 7340032, 16777216, 29360128, 67108864, 117440512, 268435456, 469762048, 1073741824, 1879048192 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

LINKS

Table of n, a(n) for n=1..31.

Index entries for linear recurrences with constant coefficients, signature (0,4).

FORMULA

For even indexed terms, a(n) = 2^n. For odd indexed terms, a(n) = 7 * 2^(n-3).

G.f.: -x*(x+1)*(3*x+1)/(2*x-1)/(2*x+1). - R. J. Mathar, Nov 14 2007

a(n) = 4*a(n-2) for n > 3; a(1) = 1, a(2) = 4, a(3) = 7. [From Klaus Brockhaus, Nov 26 2009]

EXAMPLE

a(4) = 16 = sum of row 4 terms of triangle A133599 = (3 + 7 + 5 + 1).

a(4) = 16 = 2^4.

a(7) = 112 = 7 * 2^4 = 7 * 16.

PROG

(PARI) {vector(31, n, if(n==1, 1, if(n%2>0, 7*2^(n-3), 2^n)))} /* Klaus Brockhaus, Nov 26 2009 */

CROSSREFS

Cf. A133599, A000302 (bisection), A002042 (bisection, n>2).

Sequence in context: A254143 A025619 A093210 * A240736 A286741 A298344

Adjacent sequences:  A133597 A133598 A133599 * A133601 A133602 A133603

KEYWORD

nonn,easy

AUTHOR

Gary W. Adamson, Sep 18 2007

STATUS

approved

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Last modified August 25 15:34 EDT 2019. Contains 326324 sequences. (Running on oeis4.)