This site is supported by donations to The OEIS Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A263271 Square array A(row,col): A(row,0) = row and for col >= 1, if A262686(row) is 0, then A(row,col) = 0, otherwise A(row,col) = A(A262686(row),col-1). 4
 0, 2, 1, 6, 4, 2, 12, 8, 6, 3, 18, 0, 12, 5, 4, 22, 0, 18, 7, 8, 5, 30, 0, 22, 0, 0, 7, 6, 34, 0, 30, 0, 0, 0, 12, 7, 42, 0, 34, 0, 0, 0, 18, 0, 8, 46, 0, 42, 0, 0, 0, 22, 0, 0, 9, 54, 0, 46, 0, 0, 0, 30, 0, 0, 11, 10, 58, 0, 54, 0, 0, 0, 34, 0, 0, 16, 14, 11 (list; table; graph; refs; listen; history; text; internal format)
 OFFSET 0,2 COMMENTS The square array A(row>=0, col>=0) is read by downwards antidiagonals as: A(0,0), A(0,1), A(1,0), A(0,2), A(1,1), A(2,0), A(0,3), A(1,2), A(2,1), A(3,0), ... Each row n lists all the nodes in A263267-tree that one encounters when one starts from node n and always chooses the largest possible child of it (A262686), and then the largest possible child of that child, etc, until a leaf-child (one of the terms of A045765) is encountered, after which the rest of the row contains only zeros. LINKS Antti Karttunen, Table of n, a(n) for n = 0..10439; the first 144 antidiagonals FORMULA A(row,0) = row and for col >= 1, if A262686(row) is 0, then A(row,col) = 0, otherwise A(row,col) = A(A262686(row),col-1). A(0,0) = 0, A(0,1) = 2; if col = 0, A(row,0) = row; and for col > 0, if A(row,col-1) = 0, then A(row,col) = 0, otherwise A(row,col) = A262686(A(row,col-1)). [Another, perhaps more intuitive recurrence for this array.] - Antti Karttunen, Dec 21 2015 EXAMPLE The top left corner of the array:    0,  2,  6, 12, 18, 22, 30, 34, 42, 46, 54, 58, 66,  0,  0,  0,  0    1,  4,  8,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0    2,  6, 12, 18, 22, 30, 34, 42, 46, 54, 58, 66,  0,  0,  0,  0,  0    3,  5,  7,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0    4,  8,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0    5,  7,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0    6, 12, 18, 22, 30, 34, 42, 46, 54, 58, 66,  0,  0,  0,  0,  0,  0    7,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0    8,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0    9, 11, 16, 24,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0   10, 14, 20,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0   11, 16, 24,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0   12, 18, 22, 30, 34, 42, 46, 54, 58, 66,  0,  0,  0,  0,  0,  0,  0   13,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0   14, 20,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0   15, 17, 21, 23, 27, 36,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0   ... PROG (Scheme) (define (A263271 n) (A263271bi (A002262 n) (A025581 n))) (define (A263271bi row col) (cond ((zero? col) row) ((A262686 row) => (lambda (lad) (if (zero? lad) lad (A263271bi lad (- col 1))))))) ;; An alternative implementation, reflecting the new recurrence: (define (A263271bi row col) (cond ((zero? col) row) ((and (zero? row) (= 1 col)) 2) ((zero? (A263271bi row (- col 1))) 0) (else (A262686 (A263271bi row (- col 1)))))) CROSSREFS Column 0: A001477, Column 1: A262686. Cf. A264971 (number of significant terms on each row, position where the first trailing zero-term occurs). Cf. A264970. Cf. also A000005, A045765, A263267. See also array A265751 constructed in the same way, but obtained by following always the smallest child A082284, instead of the largest child A262686. Sequence in context: A135885 A162312 A141715 * A098697 A193094 A021466 Adjacent sequences:  A263268 A263269 A263270 * A263272 A263273 A263274 KEYWORD nonn,tabl AUTHOR Antti Karttunen, Nov 29 2015 STATUS approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified August 17 22:59 EDT 2019. Contains 326059 sequences. (Running on oeis4.)