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A152537 Convolution sequence: convolved with A000041 = powers of 2, (A000079). +0
4
1, 1, 1, 2, 4, 9, 18, 37, 74, 148, 296, 592, 1183 (list; graph; listen)
OFFSET

0,4

FORMULA

Construct an array of rows such that n-th row = partial sums of (n-1)-th row

of A010815: (1, -1, -1, 0, 0, 1, 0, 1,...).

A152537 = sums of antidiagonal terms of the array.

The sequence may be obtained directly from the following set of operations:

Our given sequence = A000041: (1, 1, 2, 3, 5, 7, 11,...). Delete the first

"1" then consider (1, 2, 3, 5, 7, 11,...) as an operator Q which we write in reverse with 1,2,3,...terms for each operation. Letting R = the target sequence (1,2,4,8,...); we begin a(0) = 1, a(1) = 1, then perform successive

operations of: "next term in (1,2,4,...) - dot product of Q*R" where Q is

written right to left and R (the ongoing result) written left to right).

Examples: Given 4 terms Q, R, we have: (5,3,2,1) dot (1,1,1,2) = (5+3+2+2) =

12, which we subtract from 16, = 4.

Given 5 terms of Q,R and A152537, we have (7,5,3,2,1) dot (1,1,1,2,4) = 23

which is subtracted from 32 giving 9. Continue with analogous operations to generate the series.

a(n)=sum_{j=0..n} A010815(j)*2^(n-j). G.f.: A000079(x)/A000041(x) = A010815(x)/(1-2x), where A......(x) denotes the g.f. of the associated sequence. [From R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Dec 09 2008]

EXAMPLE

a(5) = 9 = 32 - 23 = (32 - ((7,5,3,2,1) dot (1,1,1,2,4)))

(1,1,2,3) convolved with (1,1,1,2) = 8, where (1,1,2,3...) = the first four partition numbers.

CROSSREFS

Cf. A010815, A000041, A000079, A152538

Sequence in context: A033138 A155803 A056185 this_sequence A081253 A118255 A019299

Adjacent sequences: A152534 A152535 A152536 this_sequence A152538 A152539 A152540

KEYWORD

nonn

AUTHOR

Gary W. Adamson (qntmpkt(AT)yahoo.com), Dec 06 2008

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Last modified November 27 22:38 EST 2009. Contains 167602 sequences.


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