A353430 Number of integer compositions of n that are empty, a singleton, or whose own run-lengths are a consecutive subsequence that is already counted.
1, 1, 1, 1, 2, 1, 3, 1, 1, 4, 5, 7, 9, 11, 15, 16, 22, 25, 37, 37, 45
Offset: 0
Examples
The a(n) compositions for selected n (A..E = 10..14): n=4: n=6: n=9: n=10: n=12: n=14: ----------------------------------------------------------- (4) (6) (9) (A) (C) (E) (22) (1122) (333) (2233) (2244) (2255) (2211) (121122) (3322) (4422) (5522) (221121) (131122) (151122) (171122) (221131) (221124) (221126) (221142) (221135) (221151) (221153) (241122) (221162) (421122) (221171) (261122) (351122) (531122) (621122) (122121122) (221121221)
Crossrefs
Programs
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Mathematica
yoyQ[y_]:=Length[y]<=1||MemberQ[Join@@Table[Take[y,{i,j}],{i,Length[y]},{j,i,Length[y]}],Length/@Split[y]]&&yoyQ[Length/@Split[y]]; Table[Length[Select[Join@@Permutations/@IntegerPartitions[n],yoyQ]],{n,0,15}]