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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.

A342527 Number of compositions of n with alternating parts equal.

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%I A342527 #10 Mar 24 2021 22:19:32
%S A342527 1,1,2,4,6,8,11,12,16,17,21,20,29,24,31,32,38,32,46,36,51,46,51,44,69,
%T A342527 51,61,60,73,56,87,60,84,74,81,76,110,72,91,88,115,80,123,84,117,112,
%U A342527 111,92,153,101,132,116,139,104,159,120,161,130,141,116,205,120,151,156,178,142,195,132,183,158
%N A342527 Number of compositions of n with alternating parts equal.
%C A342527 These are finite sequences q of positive integers summing to n such that q(i) = q(i+2) for all possible i.
%H A342527 Gus Wiseman, <a href="/A069916/a069916.txt">Sequences counting and ranking partitions and compositions by their differences and quotients</a>.
%F A342527 a(n) = 1 + n + A000203(n) - 2*A000005(n).
%F A342527 a(n) = A065608(n) + A062968(n).
%e A342527 The a(1) = 1 through a(8) = 16 compositions:
%e A342527   (1)  (2)   (3)    (4)     (5)      (6)       (7)        (8)
%e A342527        (11)  (12)   (13)    (14)     (15)      (16)       (17)
%e A342527              (21)   (22)    (23)     (24)      (25)       (26)
%e A342527              (111)  (31)    (32)     (33)      (34)       (35)
%e A342527                     (121)   (41)     (42)      (43)       (44)
%e A342527                     (1111)  (131)    (51)      (52)       (53)
%e A342527                             (212)    (141)     (61)       (62)
%e A342527                             (11111)  (222)     (151)      (71)
%e A342527                                      (1212)    (232)      (161)
%e A342527                                      (2121)    (313)      (242)
%e A342527                                      (111111)  (12121)    (323)
%e A342527                                                (1111111)  (1313)
%e A342527                                                           (2222)
%e A342527                                                           (3131)
%e A342527                                                           (21212)
%e A342527                                                           (11111111)
%t A342527 Table[Length[Select[Join@@Permutations/@IntegerPartitions[n],SameQ@@Plus@@@Reverse/@Partition[#,2,1]&]],{n,0,15}]
%Y A342527 The odd-length case is A062968.
%Y A342527 The even-length case is A065608.
%Y A342527 The version with alternating parts unequal is A224958 (unordered: A000726).
%Y A342527 The version with alternating parts weakly decreasing is A342528.
%Y A342527 A000005 counts constant compositions.
%Y A342527 A000041 counts weakly increasing (or weakly decreasing) compositions.
%Y A342527 A000203 adds up divisors.
%Y A342527 A002843 counts compositions with all adjacent parts x <= 2y.
%Y A342527 A003242 counts anti-run compositions.
%Y A342527 A175342 counts compositions with constant differences.
%Y A342527 A342495 counts compositions with constant first quotients.
%Y A342527 A342496 counts partitions with constant first quotients (strict: A342515, ranking: A342522).
%Y A342527 Cf. A001522, A008965, A048004, A059966, A064410, A064428, A069916, A114921, A167606, A325545, A325557.
%K A342527 nonn
%O A342527 0,3
%A A342527 _Gus Wiseman_, Mar 24 2021