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 A256537 First differences of corner sequence A256536 associated with A151723. 3
 1, 3, 5, 9, 9, 9, 17, 25, 17, 9, 17, 29, 37, 33, 41, 57, 33, 9, 17, 29, 37, 37, 53, 85, 85, 49, 41, 73, 101, 93, 101, 125, 65, 9, 17, 29, 37, 37, 53, 85, 85, 53, 53, 93, 133, 141, 149, 197, 181, 81, 41, 73, 101, 109, 141, 221, 253, 173, 117, 173, 249, 237, 237, 265, 129 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 COMMENTS Number of cells turned ON at n-th stage in one of the outside corners of an infinite hexagon-shaped structure on hexagonal grid. For an animation see "The movie version" in Links section. LINKS David Applegate, The movie version N. J. A. Sloane, Catalog of Toothpick and Cellular Automata Sequences in the OEIS FORMULA a(1) = 1; a(2) = 3. It appears that a(n) = 1 + ((A151724(n) + A151724(n-1))/3, n >= 3. It appears that a(n) = 1 + ((A151723(n) - A151723(n-2))/3, n >= 3. It appears that a(n) = 1 + 2*(A170898(n-2) + A170898(n-3)), n >= 3. a(3) = 5. It appears that a(n) = 1 + 2*(A169779(n-2) - A169779(n-4)), n >= 4. EXAMPLE Written as an irregular triangle in which the row lengths are the absolute values of the terms of A141531, the sequence begins: 1; 3; 5; 9, 9; 9,17,25,17; 9,17,29,37,33,41,57,33; 9,17,29,37,37,53,85,85,49,41,73,101, 93,101,125, 65; 9,17,29,37,37,53,85,85,53,53,93,133,141,149,197,181,81,41,73,101,109,141,221,253,173,117,173,249,237,237,265,129; ... It appears that the right border gives A083318, whose representation in base 2 gives A000533. CROSSREFS Cf. A000533, A083318, A141531, A151723, A151724, A169779, A170898, A256536. Sequence in context: A176445 A292863 A160173 * A092996 A141264 A062949 Adjacent sequences:  A256534 A256535 A256536 * A256538 A256539 A256540 KEYWORD nonn,tabf AUTHOR Omar E. Pol, Apr 02 2015 STATUS approved

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Last modified August 10 16:56 EDT 2020. Contains 336381 sequences. (Running on oeis4.)