1,3

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.

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, 1;

....

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.

Cf. A160552, A139250

Sequence in context: A152197 A049342 A112966 this_sequence A128830 A090387 A030329

Adjacent sequences: A160567 A160568 A160569 this_sequence A160571 A160572 A160573

nonn,tabl,easy,more

Gary W. Adamson (qntmpkt(AT)yahoo.com), May 19 2009