# Greetings from The On-Line Encyclopedia of Integer Sequences! http://oeis.org/ Search: id:a355802 Showing 1-1 of 1 %I A355802 #13 Jul 19 2022 10:43:31 %S A355802 1,1,1,1,2,1,1,2,2,1,1,2,2,2,1,1,2,3,3,2,1,1,2,3,4,3,2,1,1,2,3,4,4,3, %T A355802 2,1,1,2,3,5,6,5,3,2,1,1,2,3,5,7,7,5,3,2,1,1,2,3,5,7,8,7,5,3,2,1,1,2, %U A355802 3,5,8,11,11,8,5,3,2,1,1,2,3,5,8,12,14,12,8,5,3,2,1 %N A355802 A variant of Pascal's triangle (A007318) where new rows are added cyclically below, to the right and to the left. %C A355802 The procedure to build the present triangle is as follows: %C A355802 - row 0 contains a single 1: %C A355802 . 1 %C A355802 - row 1 is added below, each new term is the sum of the adjacent prior terms: %C A355802 . 1 %C A355802 . --- %C A355802 . 1 1 %C A355802 - row 2 is added to the right, each new term is the sum of the adjacent prior terms: %C A355802 . 1 %C A355802 . \ %C A355802 . 1 \ 2 %C A355802 . \ %C A355802 . 1 1 \ 1 %C A355802 - row 3 is added to the left, each new term is the sum of the adjacent prior terms: %C A355802 . 1 %C A355802 . / %C A355802 . 2 / 1 %C A355802 . / %C A355802 . 2 / 1 2 %C A355802 . / %C A355802 . 1 / 1 1 1 %C A355802 - row 4 is added below, each new term is the sum of the adjacent prior terms: %C A355802 . 1 %C A355802 . %C A355802 . 2 1 %C A355802 . %C A355802 . 2 1 2 %C A355802 . %C A355802 . 1 1 1 1 %C A355802 . --------------- %C A355802 . 1 2 2 2 1 %C A355802 - and so on. %H A355802 Rémy Sigrist, Table of n, a(n) for n = 0..10010 %H A355802 Rémy Sigrist, Illustration of the odd terms among the first 2^9 rows %H A355802 Rémy Sigrist, PARI program %H A355802 Index entries for triangles and arrays related to Pascal's triangle %F A355802 T(n, 0) = T(n, n) = 1. %F A355802 T(n, k) = T(n, n-k). %e A355802 Triangle begins: %e A355802 1; %e A355802 1, 1; %e A355802 1, 2, 1; %e A355802 1, 2, 2, 1; %e A355802 1, 2, 2, 2, 1; %e A355802 1, 2, 3, 3, 2, 1; %e A355802 1, 2, 3, 4, 3, 2, 1; %e A355802 1, 2, 3, 4, 4, 3, 2, 1; %e A355802 1, 2, 3, 5, 6, 5, 3, 2, 1; %e A355802 1, 2, 3, 5, 7, 7, 5, 3, 2, 1; %e A355802 1, 2, 3, 5, 7, 8, 7, 5, 3, 2, 1; %e A355802 1, 2, 3, 5, 8, 11, 11, 8, 5, 3, 2, 1; %e A355802 1, 2, 3, 5, 8, 12, 14, 12, 8, 5, 3, 2, 1; %e A355802 ... %o A355802 (PARI) See Links section. %Y A355802 Cf. A007318, A355806. %K A355802 nonn,tabl %O A355802 0,5 %A A355802 _Rémy Sigrist_, Jul 17 2022 # Content is available under The OEIS End-User License Agreement: http://oeis.org/LICENSE