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A169946 Triangle read by rows: A169945 with rows reversed. 0
1, 1, 1, 2, 1, 1, 3, 3, 1, 1, 2, 8, 4, 1, 1, 3, 6, 16, 5, 1, 1, 2, 11, 14, 29, 6, 1, 1, 3, 9, 29, 29, 49, 7, 1, 1, 2, 14, 22, 74, 52, 82, 8, 1, 1, 3, 12, 42, 58, 160, 96, 130, 9, 1, 1, 2, 17, 30, 126, 128, 344, 160, 205, 10, 1, 1, 3, 15, 53, 98, 314, 294, 676, 277, 305, 11 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,4

COMMENTS

The heuristic formula for the third column (verified for 2<=n<=21) is 3*n/2+7*(1-(-1)^n)/4. [From R. J. Mathar, Aug 02 2010]

LINKS

Table of n, a(n) for n=0..75.

Index entries for sequences related to carryless arithmetic

FORMULA

Wanted: a recurrence. Are any of A169940-A169954 related to any other entries in the OEIS?

EXAMPLE

Triangle begins:

[1, 1]

[1, 2, 1]

[1, 3, 3, 1]

[1, 2, 8, 4, 1]

[1, 3, 6, 16, 5, 1]

[1, 2, 11, 14, 29, 6, 1]

[1, 3, 9, 29, 29, 49, 7, 1]

[1, 2, 14, 22, 74, 52, 82, 8, 1]

[1, 3, 12, 42, 58, 160, 96, 130, 9, 1]

[1, 2, 17, 30, 126, 128, 344, 160, 205, 10, 1]

[1, 3, 15, 53, 98, 314, 294, 676, 277, 305, 11, 1]

[1, 2, 20, 38, 185, 232, 796, 576, 1333, 450, 450, 12, 1]

[1, 3, 18, 64, 147, 501, 628, 1796, 1177, 2477, 712, 654, 13, 1]

[1, 2, 23, 46, 251, 368, 1425, 1370, 4075, 2212, 4563, 1086, 947, 14, 1]

[1, 3, 21, 75, 205, 729, 1117, 3515, 3265, 8535, 4289, 7997, 1657, 1343, 15, 1]

...

CROSSREFS

Related to thickness: A169940-A169954, A061909.

Sequence in context: A080381 A080396 A155582 * A160832 A157458 A174447

Adjacent sequences:  A169943 A169944 A169945 * A169947 A169948 A169949

KEYWORD

nonn,tabf

AUTHOR

N. J. A. Sloane, Aug 01 2010

STATUS

approved

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Last modified April 12 22:03 EDT 2021. Contains 342933 sequences. (Running on oeis4.)