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 A182993 #20 Nov 23 2019 04:05:49 %S A182993 1,2,5,12,21,39,73,118,198,326,510,797,1234,1854,2778,4122,6014,8717, %T A182993 12550,17849,25252,35486,49447,68540,94480,129378,176339,239165, %U A182993 322676,433487,579907,772318,1024691,1354445,1783504 %N A182993 Number of parts of the n-th subshell of the head of the last section of the set of partitions of any odd integer >= 2n+1. %C A182993 The last section of the set of partitions of 2n+1 contains n subshells. %C A182993 Also first differences of A182735. - _Omar E. Pol_, Mar 03 2011 %F A182993 a(n) = A138135(2n+1) - A138135(2n-1). %e A182993 a(5)=21 because the 5th subshell of the head of the last section of any odd integer >= 11 looks like this: %e A182993 (11 . . . . . . . . . . ) %e A182993 ( 6 . . . . . 5 . . . . ) %e A182993 ( 7 . . . . . . 4 . . . ) %e A182993 ( 8 . . . . . . . 3 . . ) %e A182993 ( 4 . . . 4 . . . 3 . . ) %e A182993 ( 5 . . . . 3 . . 3 . . ) %e A182993 . (2 . ) %e A182993 . (2 . ) %e A182993 . (2 . ) %e A182993 . (2 . ) %e A182993 . (2 . ) %e A182993 . (2 . ) %e A182993 . (2 . ) %e A182993 . (2 . ) %e A182993 The subshell has 21 parts, so a(5)=21. %Y A182993 Cf. A135010, A138135, A182735, A182743, A182983, A182992, A182995. %K A182993 nonn %O A182993 1,2 %A A182993 _Omar E. Pol_, Feb 06 2011 %E A182993 More terms from _Omar E. Pol_, Mar 03 2011