The OEIS mourns the passing of Jim Simons and is grateful to the Simons Foundation for its support of research in many branches of science, including the OEIS.
The OEIS is supported by the many generous donors to the OEIS Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A079809 Consider a triangle in which the 2n-th row contains first 2n positive integers in increasing order and the (2n+1)-st row contains first 2n+1 positive integers in decreasing order; sequence contains concatenation of numbers read upward at a 45-degree angle. 4

%I #11 Dec 14 2023 15:40:08

%S 1,1,32,12,521,143,7234,1632,92541,18345,1127436,1103652,13294561,

%T 11238547,1521147638,1143105672,17213496581,11631258749,

%U 19215411678310,1183145107692,212174136985101,120316512789411,232194156118710312

%N Consider a triangle in which the 2n-th row contains first 2n positive integers in increasing order and the (2n+1)-st row contains first 2n+1 positive integers in decreasing order; sequence contains concatenation of numbers read upward at a 45-degree angle.

%H G. C. Greubel, <a href="/A079809/b079809.txt">Table of n, a(n) for n = 1..715</a>

%e Triangle begins with:

%e 1;

%e 1 2;

%e 3 2 1;

%e 1 2 3 4;

%e 5 4 3 2 1;

%e 1 2 3 4 5 6;

%t a[n_] := FromDigits[Join@@Table[IntegerDigits[If[OddQ[n+1-i], n+2-2i, i]], {i, 1, Ceiling[n/2]}]]

%Y Cf. A079808, A079810.

%K base,nonn

%O 1,3

%A _Amarnath Murthy_, Feb 10 2003

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

Last modified May 22 18:14 EDT 2024. Contains 372758 sequences. (Running on oeis4.)