cp's OEIS Frontend

A357775 Numbers k with the property that the symmetric representation of sigma(k) has seven parts.

%I A357775 #10 Oct 23 2022 23:38:19
%S A357775 357,399,441,483,513,567,609,621,651,729,759,777,783,837,861,891,957,
%T A357775 999,1023,1053,1089,1107,1131,1161,1209,1221,1269,1287,1323,1353,1419,
%U A357775 1431,1443,1521,1551,1595,1599,1677,1705,1749,1815,1833,1887,1947,1989,2013,2035,2067,2091,2145,2193,2223,2255
%N A357775 Numbers k with the property that the symmetric representation of sigma(k) has seven parts.
%F A357775 A237271(a(n)) = 7.
%e A357775 357 is in the sequence because the 357th row of A237593 is [179, 60, 31, 18, 12, 9, 7, 6, 4, 4, 3, 3, 2, 3, 2, 1, 2, 2, 1, 1, 2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 1, 1, 2, 2, 1, 2, 3, 2, 3, 3, 4, 4, 6, 7, 9, 12, 18, 31, 60, 179], and the 356th row of the same triangle is [179, 60, 30, 18, 13, 9, 6, 6, 4, 4, 3, 3, 3, 2, 2, 2, 1, 2, 1, 2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 1, 2, 1, 2, 2, 2, 3, 3, 3, 4, 4, 6, 6, 9, 13, 18, 30, 60, 179], therefore between both symmetric Dyck paths there are seven parts: [179, 61, 29, 38, 29, 61, 179].
%e A357775 Note that the sum of these parts is 179 + 61 + 29 + 38 + 29 + 61 + 179 = 576, equaling the sum of the divisors of 357: 1 + 3 + 7 + 17 + 21 + 51 + 119 + 357 = 576.
%e A357775 (The diagram of the symmetric representation of sigma(357) = 576 is too large to include.)
%Y A357775 Column 7 of A240062.
%Y A357775 Cf. A237270 (the parts), A237271 (number of parts), A238443 = A174973 (one part), A239929 (two parts), A279102 (three parts), A280107 (four parts), A320066 (five parts), A320511 (six parts).
%Y A357775 Cf. A018411, A196020, A236104, A235791, A237591, A237593, A239663, A266094.
%K A357775 nonn
%O A357775 1,1
%A A357775 _Omar E. Pol_, Oct 12 2022