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 A230849 A075526 and A000012 interleaved. 3
 1, 1, 1, 1, 2, 1, 2, 1, 4, 1, 2, 1, 4, 1, 2, 1, 4, 1, 6, 1, 2, 1, 6, 1, 4, 1, 2, 1, 4, 1, 6, 1, 6, 1, 2, 1, 6, 1, 4, 1, 2, 1, 6, 1, 4, 1, 6, 1, 8, 1, 4, 1, 2, 1, 4, 1, 2, 1, 4, 1, 14, 1, 4, 1, 6, 1, 2, 1, 10, 1, 2, 1, 6, 1, 6, 1, 4, 1, 6, 1, 6, 1, 2, 1, 10, 1, 2, 1 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,5 COMMENTS a(n) is also the length of the n-th edge of a staircase which represents the function pi(x) on the first quadrant of the square grid, see A000720. a(2n-1) is the length of the n-th horizontal edge in the staircase. a(2n) is the length of the n-th vertical edge in the staircase. For another version see A230850. LINKS Antti Karttunen, Table of n, a(n) for n = 1..20000 EXAMPLE Illustration of initial terms, n = 1..22: . 1                                                            _ _| 1                                                _ _ _ _ _ _| 1                                        _ _ _ _| 1                                    _ _| 1                            _ _ _ _| 1                        _ _| 1                _ _ _ _| 1            _ _| 1        _ _| 1      _| 1    _| . .    1 1   2   2       4   2       4   2       4           6   2 . Drawing vertical line segments below the staircase (as shown below) we have that the number of cells in the vertical bars gives A000720. Drawing horizontal line segments above the staircase we have that the number of cells in the k-th horizontal bar is A006093(k). .    _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 30  |_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _| 28  |_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _| | | 22  |_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _| | | | | | | | | 18  |_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _| | | | | | | | | | | | | 16  |_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _| | | | | | | | | | | | | | | 12  |_ _ _ _ _ _ _ _ _ _ _ _| | | | | | | | | | | | | | | | | | | 10  |_ _ _ _ _ _ _ _ _ _| | | | | | | | | | | | | | | | | | | | | 6   |_ _ _ _ _ _| | | | | | | | | | | | | | | | | | | | | | | | | 4   |_ _ _ _| | | | | | | | | | | | | | | | | | | | | | | | | | | 2   |_ _| | | | | | | | | | | | | | | | | | | | | | | | | | | | | 1   |_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_| . .    0 1 2 2 3 3 4 4 4 4 5 5 6 6 6 6 7 7 8 8 8 8 9 9 9 9 9 9 10 10 . PROG (PARI) A230849(n) = if((n%2)&&(n>1), prime((n+1)/2)-prime(((n+1)/2)-1), 1); \\ Antti Karttunen, Dec 23 2018 CROSSREFS Cf. A000012, A000040, A000720, A001223, A006093, A007504, A046992, A075526, A141042, A152535, A230850. Sequence in context: A235918 A071222 A067005 * A135517 A327395 A327404 Adjacent sequences:  A230846 A230847 A230848 * A230850 A230851 A230852 KEYWORD nonn AUTHOR Omar E. Pol, Nov 01 2013 STATUS approved

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Last modified April 10 02:39 EDT 2020. Contains 333392 sequences. (Running on oeis4.)