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.
%I A342334 #14 Mar 12 2021 04:03:35 %S A342334 1,1,1,2,3,4,6,11,16,23,35,54,82,125,193,294,447,680,1037,1580,2408, %T A342334 3676,5606,8544,13024,19860,30277,46155,70374,107300,163586,249397, %U A342334 380235,579705,883810,1347467,2054371,3132102,4775211,7280321,11099613,16922503,25800136,39335052,59970425,91431195 %N A342334 Number of compositions of n with all adjacent parts (x, y) satisfying x >= 2y or y > 2x. %C A342334 Also the number of compositions of n with all adjacent parts (x, y) satisfying x > 2y or y >= 2x. %e A342334 The a(1) = 1 through a(8) = 16 compositions: %e A342334 (1) (2) (3) (4) (5) (6) (7) (8) %e A342334 (12) (13) (14) (15) (16) (17) %e A342334 (31) (41) (24) (25) (26) %e A342334 (131) (51) (52) (62) %e A342334 (141) (61) (71) %e A342334 (312) (124) (125) %e A342334 (151) (152) %e A342334 (241) (161) %e A342334 (313) (251) %e A342334 (412) (314) %e A342334 (1312) (413) %e A342334 (512) %e A342334 (1241) %e A342334 (1313) %e A342334 (1412) %e A342334 (3131) %t A342334 Table[Length[Select[Join@@Permutations/@IntegerPartitions[n],And@@Table[#[[i]]>=2*#[[i-1]]||#[[i-1]]>2*#[[i]],{i,2,Length[#]}]&]],{n,0,15}] %Y A342334 The unordered version (partitions) is A342098 or A000929 (multisets). %Y A342334 The version not allowing equality (i.e., strict relations) is A342332. %Y A342334 The version allowing equality (i.e., non-strict relations) is A342333. %Y A342334 Reversing operators and changing 'or' into 'and' gives A342338. %Y A342334 A002843 counts compositions with adjacent parts x <= 2y. %Y A342334 A154402 counts partitions with adjacent parts x = 2y. %Y A342334 A224957 counts compositions with x <= 2y and y <= 2x (strict: A342342). %Y A342334 A274199 counts compositions with adjacent parts x < 2y. %Y A342334 A342094 counts partitions with adjacent parts x <= 2y (strict: A342095). %Y A342334 A342096 counts partitions without adjacent x >= 2y (strict: A342097). %Y A342334 A342330 counts compositions with x < 2y and y < 2x (strict: A342341). %Y A342334 A342331 counts compositions with adjacent parts x = 2y or y = 2x. %Y A342334 A342335 counts compositions with adjacent parts x >= 2y or y = 2x. %Y A342334 A342337 counts partitions with adjacent parts x = y or x = 2y. %Y A342334 Cf. A003114, A003242, A034296, A167606, A342083, A342084, A342087, A342191, A342336, A342340. %K A342334 nonn %O A342334 0,4 %A A342334 _Gus Wiseman_, Mar 10 2021 %E A342334 More terms from _Joerg Arndt_, Mar 12 2021