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A361507
a(0) = 1; thereafter a(n) = floor((9/4)*a(n-1)) + 1.
4
1, 3, 7, 16, 37, 84, 190, 428, 964, 2170, 4883, 10987, 24721, 55623, 125152, 281593, 633585, 1425567, 3207526, 7216934, 16238102, 36535730, 82205393, 184962135, 416164804, 936370810, 2106834323, 4740377227, 10665848761, 23998159713, 53995859355, 121490683549, 273354037986, 615046585469, 1383854817306, 3113673338939
OFFSET
0,2
REFERENCES
N. Tokuda, An efficient Shell's method of sorting by generalized scheme, Department of Computer Science, Utunomiya University, 1989; 10 pages plus 9 unnumbered pages of tables and charts.
MATHEMATICA
NestList[Floor[9/4#]+1&, 1, 50] (* Paolo Xausa, Dec 02 2023 *)
CROSSREFS
Other sequences used for Shell sort: A003462, A033622, A036562, A036564, A036569, A055875, A055876, A108870, A361506.
Sequence in context: A033303 A078056 A173761 * A124671 A188626 A123392
KEYWORD
nonn
AUTHOR
N. J. A. Sloane, Mar 20 2023, following a suggestion from Don Knuth.
STATUS
approved