cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A182285 Triangle read by rows: T(n,k) = sum of all parts in the k-th zone of the last section of the set of partitions of n.

This page as a plain text file.
%I A182285 #20 Dec 01 2013 13:35:01
%S A182285 1,1,2,1,1,3,1,1,1,4,4,1,1,1,1,1,5,5,1,1,1,1,1,1,1,6,6,6,6,1,1,1,1,1,
%T A182285 1,1,1,1,1,1,7,7,7,7,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,8,8,8,8,8,8,8,1,1,
%U A182285 1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1
%N A182285 Triangle read by rows: T(n,k) = sum of all parts in the k-th zone of the last section of the set of partitions of n.
%C A182285 Row n lists A000041(n-1) 1's together with A002865(n) n's.
%e A182285 Illustration of three arrangements of the last section of the set of partitions of 7 and the zone numbers:
%e A182285 --------------------------------------------------------
%e A182285 Zone \   a)                    b)                    c)
%e A182285 --------------------------------------------------------
%e A182285 15      (7)                   (7)       (. . . . . . 7)
%e A182285 14      (4+3)               (4+3)       (. . . 4 . . 3)
%e A182285 13      (5+2)               (5+2)       (. . . . 5 . 2)
%e A182285 12      (3+2+2)           (3+2+2)       (. . 3 . 2 . 2)
%e A182285 11        (1)                 (1)                   (1)
%e A182285 10          (1)               (1)                   (1)
%e A182285 9           (1)               (1)                   (1)
%e A182285 8             (1)             (1)                   (1)
%e A182285 7           (1)               (1)                   (1)
%e A182285 6             (1)             (1)                   (1)
%e A182285 5             (1)             (1)                   (1)
%e A182285 4               (1)           (1)                   (1)
%e A182285 3               (1)           (1)                   (1)
%e A182285 2                 (1)         (1)                   (1)
%e A182285 1                   (1)       (1)                   (1)
%e A182285 .
%e A182285 For n = 7 and k = 12 we can see that in the 12th zone of the last section of 7 the parts are 3, 2, 2, therefore T(7,12) = 3+2+2 = 7.
%e A182285 Written as a triangle begins:
%e A182285 1;
%e A182285 1,2;
%e A182285 1,1,3;
%e A182285 1,1,1,4,4;
%e A182285 1,1,1,1,1,5,5;
%e A182285 1,1,1,1,1,1,1,6,6,6,6;
%e A182285 1,1,1,1,1,1,1,1,1,1,1,7,7,7,7;
%e A182285 1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,8,8,8,8,8,8,8;
%Y A182285 Row n has length A000041(n). Row sums give A138879.
%Y A182285 Cf. A000041, A002865, A135010, A138121, A182284, A193173.
%K A182285 nonn,tabf
%O A182285 1,3
%A A182285 _Omar E. Pol_, Apr 23 2012