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A350548
Irregular triangle T(n,k) read by rows in which row n lists the iterates of the A350515 map from n to 0.
1
0, 1, 0, 2, 1, 0, 3, 5, 8, 4, 1, 0, 4, 1, 0, 5, 8, 4, 1, 0, 6, 3, 5, 8, 4, 1, 0, 7, 2, 1, 0, 8, 4, 1, 0, 9, 14, 7, 2, 1, 0, 10, 3, 5, 8, 4, 1, 0, 11, 17, 26, 13, 4, 1, 0, 12, 6, 3, 5, 8, 4, 1, 0, 13, 4, 1, 0, 14, 7, 2, 1, 0, 15, 23, 35, 53, 80, 40, 13, 4, 1, 0
OFFSET
0,4
LINKS
Emre Yolcu, Scott Aaronson and Marijn J. H. Heule, An Automated Approach to the Collatz Conjecture, arXiv:2105.14697 [cs.LO], 2021, pp. 21-25.
FORMULA
T(n,0) = n; T(n,k) = A350515(T(n,k-1)), where n >= 0 and k >= 1.
T(n,k) = (A350279(n+1,k+1)-1)/2, where n >= 0 and k >= 0.
EXAMPLE
Written as an irregular triangle, the sequence begins:
n\k 0 1 2 3 4 5 6
-------------------------------
0: 0
1: 1 0
2: 2 1 0
3: 3 5 8 4 1 0
4: 4 1 0
5: 5 8 4 1 0
6: 6 3 5 8 4 1 0
7: 7 2 1 0
8: 8 4 1 0
9: 9 14 7 2 1 0
10: 10 3 5 8 4 1 0
11: 11 17 26 13 4 1 0
...
MATHEMATICA
A350515[n_]:=If[Mod[n, 3]==1, (n-1)/3, If[Mod[n, 6]==0||Mod[n, 6]==2, n/2, (3n+1)/2]];
nrows=20; Table[NestWhileList[A350515, n, #>0&], {n, 0, nrows-1}]
CROSSREFS
KEYWORD
nonn,easy,tabf
AUTHOR
Paolo Xausa, Jan 04 2022
STATUS
approved