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A322409
Compound tribonacci sequence with a(n) = A278040(A278040(n)), for n >= 0.
7
5, 18, 29, 42, 49, 62, 73, 86, 99, 110, 123, 130, 143, 154, 167, 178, 191, 198, 211, 222, 235, 248, 259, 272, 279, 292, 303, 316, 323, 336, 347, 360, 373, 384, 397, 404, 417, 428, 441, 452, 465, 472, 485, 496, 509, 522, 533, 546, 553, 566, 577, 590, 603, 614, 627, 634, 647, 658, 671, 682, 695
OFFSET
0,1
COMMENTS
(a(n+1)) = A319968(n)-1 = A003145(A003145(n))-1, the corresponding classical compound tribonacci sequence. - Michel Dekking, Apr 04 2019
The nine sequences A308199, A319967, A319968, A322410, A322409, A322411, A322413, A322412, A322414 are based on defining the tribonacci ternary word to start with index 0 (in contrast to the usual definition, in A080843 and A092782, which starts with index 1). As a result these nine sequences differ from the compound tribonacci sequences defined in A278040, A278041, and A319966-A319972. - N. J. A. Sloane, Apr 05 2019
FORMULA
a(n) = A(A(n)) = A(A(n) + 1) - 3 = 2*(A(n) + B(n)) + n + 3, for n >= 0, where A = A278040 and B = A278039. For a proof see the W. Lang link in A278040, Proposition 9, eq. (48).
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Wolfdieter Lang, Jan 02 2019
STATUS
approved