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!)
 A244971 Number of regions in the symmetric representation of sigma(n) on the four quadrants. 7
 1, 1, 4, 1, 4, 1, 4, 1, 8, 4, 4, 1, 4, 4, 8, 1, 4, 1, 4, 1, 12, 4, 4, 1, 8, 4, 12, 1, 4, 1, 4, 1, 12, 4, 8, 1, 4, 4, 12, 1, 4, 1, 4, 4, 8, 4, 4, 1, 8, 8, 12, 4, 4, 1, 12, 1, 12, 4, 4, 1, 4, 4, 16, 1, 12, 1, 4, 4, 12, 8, 4, 1, 4, 4, 12, 4, 8, 4, 4, 1, 16, 4, 4, 1, 12, 4, 12, 1, 4, 1 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,3 COMMENTS Partial sums give A244970. Number of terraces at the n-th level (starting from the top) of the step pyramid described in A244050. - Omar E. Pol, Apr 20 2016 LINKS FORMULA a(n) = 1, if A237271(n) = 1. a(n) = 4*(A237271(n) - 1), if A237271(n) > 1. EXAMPLE From Omar E. Pol, Apr 20 2016: (Start) Illustration of the top view of the step pyramid with 16 levels: .                 _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ .                |  _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _  | .                | |_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _| | .             _ _| |  _ _ _ _ _ _ _ _ _ _ _ _ _ _  | |_ _ .           _|  _ _| |_ _ _ _ _ _ _ _ _ _ _ _ _ _| |_ _  |_ .         _|  _|  _| |  _ _ _ _ _ _ _ _ _ _ _ _  | |_  |_  |_ .        |  _|   |_ _| |_ _ _ _ _ _ _ _ _ _ _ _| |_ _|   |_  | .   _ _ _| |  _ _|     |  _ _ _ _ _ _ _ _ _ _  |     |_ _  | |_ _ _ .  |  _ _ _|_| |      _| |_ _ _ _ _ _ _ _ _ _| |_      | |_|_ _ _  | .  | | |  _ _ _|    _|_ _|  _ _ _ _ _ _ _ _  |_ _|_    |_ _ _  | | | .  | | | | |  _ _ _| |  _| |_ _ _ _ _ _ _ _| |_  | |_ _ _  | | | | | .  | | | | | | |  _ _|_|  _|  _ _ _ _ _ _  |_  |_|_ _  | | | | | | | .  | | | | | | | | |  _ _|   |_ _ _ _ _ _|   |_ _  | | | | | | | | | .  | | | | | | | | | | |  _ _|  _ _ _ _  |_ _  | | | | | | | | | | | .  | | | | | | | | | | | | |  _|_ _ _ _|_  | | | | | | | | | | | | | .  | | | | | | | | | | | | | | |  _ _  | | | | | | | | | | | | | | | .  | | | | | | | | | | | | | | | |   | | | | | | | | | | | | | | | | .  | | | | | | | | | | | | | | | |_ _| | | | | | | | | | | | | | | | .  | | | | | | | | | | | | | |_|_ _ _ _|_| | | | | | | | | | | | | | .  | | | | | | | | | | | |_|_  |_ _ _ _|  _|_| | | | | | | | | | | | .  | | | | | | | | | |_|_    |_ _ _ _ _ _|    _|_| | | | | | | | | | .  | | | | | | | |_|_ _  |_  |_ _ _ _ _ _|  _|  _ _|_| | | | | | | | .  | | | | | |_|_ _  | |_  |_ _ _ _ _ _ _ _|  _| |  _ _|_| | | | | | .  | | | |_|_ _    |_|_ _| |_ _ _ _ _ _ _ _| |_ _|_|    _ _|_| | | | .  | |_|_ _ _  |     |_  |_ _ _ _ _ _ _ _ _ _|  _|     |  _ _ _|_| | .  |_ _ _  | |_|_      | |_ _ _ _ _ _ _ _ _ _| |      _|_| |  _ _ _| .        | |_    |_ _  |_ _ _ _ _ _ _ _ _ _ _ _|  _ _|    _| | .        |_  |_  |_  | |_ _ _ _ _ _ _ _ _ _ _ _| |  _|  _|  _| .          |_  |_ _| |_ _ _ _ _ _ _ _ _ _ _ _ _ _| |_ _|  _| .            |_ _  | |_ _ _ _ _ _ _ _ _ _ _ _ _ _| |  _ _| .                | |_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _| | .                | |_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _| | .                |_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _| . Note that the above diagram contains a hidden pattern, simpler, which emerges from the front view of every corner of the step pyramid. For more information about the hidden pattern see A237593. (End) PROG (PARI) lista() = {v = readvec("b237271.txt"); for (i=1, #v, vi = v[i]; if (vi == 1, w = 1, w = 4*(vi-1)); print1(w, ", "); ); } \\ Michel Marcus, Sep 29 2014 CROSSREFS Cf. A000203, A196020, A235791, A236104, A237270, A237271, A237591, A237593, A239050, A239660, A239931-A239934, A244050, A244370, A244371, A244970, A245092. Sequence in context: A010685 A174571 A099301 * A050347 A240226 A322515 Adjacent sequences:  A244968 A244969 A244970 * A244972 A244973 A244974 KEYWORD nonn AUTHOR Omar E. Pol, Jul 08 2014 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 April 5 06:13 EDT 2020. Contains 333238 sequences. (Running on oeis4.)