cp's OEIS Frontend

A244894 Composite numbers n with the property that the symmetric representation of sigma(n) has two parts.

%I A244894 #22 Nov 09 2018 20:24:13
%S A244894 10,14,22,26,34,38,44,46,52,58,62,68,74,76,78,82,86,92,94,102,106,114,
%T A244894 116,118,122,124,134,136,138,142,146,148,152,158,164,166,172,174,178,
%U A244894 184,186,188,194,202,206,212,214,218,222,226,232,236,244,246,248,254,258,262,268,274,278,282,284,292,296,298,302,314,316,318,326,328,332,334,344,346,348,354,356,358
%N A244894 Composite numbers n with the property that the symmetric representation of sigma(n) has two parts.
%C A244894 Even numbers in A239929.
%C A244894 By definition the two parts of the symmetric representation of sigma(n) are sigma(n)/2 and sigma(n)/2.
%H A244894 R. J. Mathar, <a href="/A244894/b244894.txt">Table of n, a(n) for n = 1..999</a>
%e A244894 Illustration of the symmetric representation of sigma(n) in the second quadrant for the first four elements of this sequence: [10, 14, 22, 26].
%e A244894 .
%e A244894 .                             _ _ _ _ _ _ _ _ _ _ _ _ _ _
%e A244894 .                            |  _ _ _ _ _ _ _ _ _ _ _ _ _|
%e A244894 .                            | |
%e A244894 .                            | |
%e A244894 .                            | |  _ _ _ _ _ _ _ _ _ _ _ _
%e A244894 .                      21 _ _| | |  _ _ _ _ _ _ _ _ _ _ _|
%e A244894 .                        |_ _ _| | |
%e A244894 .                     _ _|       | |
%e A244894 .                   _|     18 _ _| |
%e A244894 .                  |         |_ _ _|
%e A244894 .            21 _ _|        _|
%e A244894 .              | |        _|
%e A244894 .     _ _ _ _ _| | 18 _ _|                _ _ _ _ _ _ _ _
%e A244894 .    |  _ _ _ _ _|   | |                 |  _ _ _ _ _ _ _|
%e A244894 .    | |      _ _ _ _| |                 | |
%e A244894 .    | |     |  _ _ _ _|             12 _| |
%e A244894 .    | |     | |                       |_ _|  _ _ _ _ _ _
%e A244894 .    | |     | |                 12 _ _|     |  _ _ _ _ _|
%e A244894 .    | |     | |              _ _ _| |    9 _| |
%e A244894 .    | |     | |             |  _ _ _|  9 _|_ _|
%e A244894 .    | |     | |             | |      _ _| |
%e A244894 .    | |     | |             | |     |  _ _|
%e A244894 .    | |     | |             | |     | |
%e A244894 .    | |     | |             | |     | |
%e A244894 .    | |     | |             | |     | |
%e A244894 .    | |     | |             | |     | |
%e A244894 .    |_|     |_|             |_|     |_|
%e A244894 .
%e A244894 n:    26      22              14      10
%e A244894 .
%e A244894 Sigma(10) =  9 +  9 = 18.
%e A244894 Sigma(14) = 12 + 12 = 24.
%e A244894 Sigma(22) = 18 + 18 = 36.
%e A244894 Sigma(26) = 21 + 21 = 42.
%e A244894 .
%Y A244894 Cf. A237271 (number of parts), A237270, A237593, A238443, A238524, A239660, A239929, A239932, A239934, A245092, A262626, A280107 (4 parts).
%K A244894 nonn
%O A244894 1,1
%A A244894 _Omar E. Pol_, Jul 07 2014
%E A244894 Extended by _R. J. Mathar_, Oct 04 2018