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A160570 Triangle read by rows, A160552 convolved with (1, 2, 2, 2,...); row sums = A139250, the Toothpick sequence. 3
1, 1, 2, 3, 2, 2, 1, 6, 2, 2, 3, 2, 6, 2, 2, 5, 6, 2, 6, 2, 2, 7, 10, 6, 2, 6, 2, 2, 1, 14, 10, 6, 2, 6, 2, 2, 3, 2, 14, 10, 6, 2, 6, 2, 2, 5, 6, 2, 14, 10, 6, 2, 6, 2, 2, 7, 10, 6, 2, 14, 10, 6, 2, 6, 2, 2, 5, 14, 10, 6, 2, 14, 10, 6, 2, 6, 2, 2, 11, 10, 14, 10, 6, 2, 14, 10, 6, 2, 6 (list; table; graph; refs; listen; history; text; internal format)
OFFSET

1,3

LINKS

Nathaniel Johnston, Table of n, a(n) for n = 1..10000

David Applegate, Omar E. Pol and N. J. A. Sloane, The Toothpick Sequence and Other Sequences from Cellular Automata

N. J. A. Sloane, Catalog of Toothpick and Cellular Automata Sequences in the OEIS

FORMULA

Construct triangle M = an infinite lower triangular Toeplitz matrix with A160552: (1, 1, 3, 1, 3, 5, 7,...) in every column. Let Q = an infinite lower triangular matrix with (1, 2, 2, 2, 2,...) as the main diagonal and the rest zeros. A160570 = M * Q.

EXAMPLE

First few rows of the triangle =

.1;

.1, 2;

.3, 2, 2;

.1, 6, 2, 2;

.3, 2, 6, 2, 2;

.5, 6, 2, 6, 2, 2;

.7, 10, 6, 2, 6, 2, 2;

.1, 14, 10, 6, 2, 6, 2, 2;

.3, 2, 14, 10, 6, 2, 6, 2, 2;

.5, 6, 2, 14, 10, 6, 2, 6, 2, 2;

....

Example: Row 4 = (1, 6, 2, 2) = (1, 3, 1, 1) dot (1, 2, 2, 2); where (1 + 6 + 2 + 2) = A139250(4), i.e. 4-th term in the Toothpick sequence.

MAPLE

T:=proc(n, k)if(k=1)then return A160552(n):else return 2*A160552(n-k+1):fi:end:

for n from 1 to 8 do for k from 1 to n do print(T(n, k)); od:od: ##Nathaniel Johnston, Apr 13 2011

CROSSREFS

Cf. A160552, A139250

Sequence in context: A152197 A049342 A112966 * A128830 A090387 A030329

Adjacent sequences:  A160567 A160568 A160569 * A160571 A160572 A160573

KEYWORD

nonn,tabl,easy

AUTHOR

Gary W. Adamson, May 19 2009

STATUS

approved

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Last modified June 18 02:45 EDT 2013. Contains 226327 sequences.