cp's OEIS Frontend

A302246 Irregular triangle read by rows in which row n lists all parts of all partitions of n, in nonincreasing order.

%I A302246 #56 Jun 17 2022 11:59:26
%S A302246 1,2,1,1,3,2,1,1,1,1,4,3,2,2,2,1,1,1,1,1,1,1,5,4,3,3,2,2,2,2,1,1,1,1,
%T A302246 1,1,1,1,1,1,1,1,6,5,4,4,3,3,3,3,2,2,2,2,2,2,2,2,1,1,1,1,1,1,1,1,1,1,
%U A302246 1,1,1,1,1,1,1,1,1,7,6,5,5,4,4,4,3,3,3,3,3,3,2,2,2,2,2,2,2,2,2,2,2,1,1,1
%N A302246 Irregular triangle read by rows in which row n lists all parts of all partitions of n, in nonincreasing order.
%C A302246 Also due to the correspondence divisor/part row n lists the terms of the n-th row of A338156 in nonincreasing order. In other words: row n lists in nonincreasing order the divisors of the terms of the n-th row of A176206. - _Omar E. Pol_, Jun 16 2022
%H A302246 Paolo Xausa, <a href="/A302246/b302246.txt">Table of n, a(n) for n = 1..9687</a>, (rows 1..18 of triangle, flattened).
%e A302246 Triangle begins:
%e A302246   1;
%e A302246   2,1,1;
%e A302246   3,2,1,1,1,1;
%e A302246   4,3,2,2,2,1,1,1,1,1,1,1;
%e A302246   5,4,3,3,2,2,2,2,1,1,1,1,1,1,1,1,1,1,1,1;
%e A302246   6,5,4,4,3,3,3,3,2,2,2,2,2,2,2,2,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1;
%e A302246   ...
%e A302246 For n = 4 the partitions of 4 are [4], [2, 2], [3, 1], [2, 1, 1], [1, 1, 1, 1]. There is only one 4, only one 3, three 2's and seven 1's, so the 4th row of this triangle is [4, 3, 2, 2, 2, 1, 1, 1, 1, 1, 1, 1].
%e A302246 On the other hand for n = 4 the 4th row of A176206 is [4, 3, 2, 2, 1, 1, 1] and the divisors of these terms are [1, 2, 4], [1, 3], [1, 2], [1, 2], [1], [1], [1] the same as the 4th row of A338156. These divisors listed in nonincreasing order give the 4th row of this triangle. - _Omar E. Pol_, Jun 16 2022
%t A302246 nrows=10;Array[ReverseSort[Flatten[IntegerPartitions[#]]]&,nrows] (* _Paolo Xausa_, Jun 16 2022 *)
%o A302246 (PARI) row(n) = my(list = List()); forpart(p=n, for (k=1, #p, listput(list, p[k]));); vecsort(Vec(list), , 4); \\ _Michel Marcus_, Jun 16 2022
%Y A302246 Both column 1 and 2 are A000027.
%Y A302246 Row n has length A006128(n).
%Y A302246 The sum of row n is A066186(n).
%Y A302246 The number of parts k in row n is A066633(n,k).
%Y A302246 The sum of all parts k in row n is A138785(n,k).
%Y A302246 The number of parts >= k in row n is A181187(n,k).
%Y A302246 The sum of all parts >= k in row n is A206561(n,k).
%Y A302246 The number of parts <= k in row n is A210947(n,k).
%Y A302246 The sum of all parts <= k in row n is A210948(n,k).
%Y A302246 First differs from A036037, A080577, A181317, A237982 and A239512 at a(13) = T(4,3).
%Y A302246 Cf. A302247 (mirror).
%Y A302246 Cf. A000041, A027550, A176206, A221529, A336812, A338156.
%K A302246 nonn,tabf
%O A302246 1,2
%A A302246 _Omar E. Pol_, Apr 05 2018