The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A229951 Number of toothpicks added at n-th stage to the toothpick structure of A229950. 5
 0, 0, 0, 1, 0, 1, 0, 1, 0, 2, 1, 2, 0, 2, 1, 2, 0, 2, 1, 3, 1, 3, 2, 3, 0, 3, 2, 3, 1, 3, 1, 3, 1, 4, 3, 4, 1, 4, 3, 4, 1, 4, 2, 4, 2, 4, 3, 4, 0, 4, 3, 5, 3, 5, 3, 5, 2, 5, 4, 5, 1, 5, 4, 5, 2, 5, 3, 5, 3, 5, 3, 5, 1, 6, 5, 6, 4, 6, 4, 6, 2, 6, 5, 6, 2, 6, 5 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,10 COMMENTS Essentially the first differences of A229950. Also [0, 0, 0] together the row sums of triangle A229940. The toothpick structure has the property that the number of exposed endpoints in the row 2k equals the number of divisors of k, if 1<2k=1. See example and Link section. LINKS Omar E. Pol, Illustration of initial terms of the divisor function (A000005), see the third picture. N. J. A. Sloane, Catalog of Toothpick and Cellular Automata Sequences in the OEIS EXAMPLE Illustration of initial terms: ---------------------------------------- n      a(n)       Diagram       A000005 ---------------------------------------- 0       0 1       0 2       0                          1 3       1         | 4       0                          2 5       1         | 6       0                          2 7       1         | 8       0                          3 9       2         | | 10      1           |              2 11      2         | | 12      0                          4 13      2         | | 14      1           |              2 15      2         | | 16      0                          4 17      2         | | 18      1           |              3 19      3         | | | 20      1             |            4 21      3         | | | 22      2           | |            2 23      3         | | | 24      0                          6 25      3         | | | 26      2           | |            2 27      3         | | | 28      1             |            4 29      3         | | | 30      1           |              4 31      3         | | | 32      1             |            5 33      4         | | | | ... CROSSREFS Cf. A000005, A139250, A139251, A229940, A229942, A229950. Sequence in context: A033794 A218856 A101665 * A165034 A193347 A115862 Adjacent sequences:  A229948 A229949 A229950 * A229952 A229953 A229954 KEYWORD nonn,tabf AUTHOR Omar E. Pol, Oct 04 2013 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 February 28 23:19 EST 2020. Contains 332353 sequences. (Running on oeis4.)