

A249299


Numbers j such that the sum of the first j terms, Sum_{k=1..j} a(k), is not in this list.


2



2, 3, 4, 6, 7, 8, 10, 11, 12, 13, 14, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 31, 32, 33, 34, 35, 36, 37, 38, 39, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 77, 78, 79, 80, 81, 82, 83, 84
(list;
graph;
refs;
listen;
history;
text;
internal format)



OFFSET

1,1


COMMENTS

Sequence A249331 lists the numbers not in this sequence, i.e., 1, 5, 9, 15, 30, 40, 51, 76, 90, 106, 123, 141, 180, 201, 223, 246, 270, 295, ... .


LINKS



EXAMPLE

The number 1 cannot appear in the sequence, since the sum of the first n=1 terms equals a(1) which is necessarily in the sequence. (Similarly for 0.)
So the smallest number that can be in the sequence is a(1)=2.
There is no (further) restriction on a(2) since 2+a(2) will always be a number not in the set {2, a(2)}. Thus the next larger number, a(2)=3, is also in this list.
The number a(3)=4 is also allowed, but because of a(1)=2 the number a(1)+a(2)=5 is excluded, as well as the number a(1)+a(2)+a(3)=2+3+4=9 because of a(2)=3.


PROG



CROSSREFS



KEYWORD

nonn


AUTHOR



STATUS

approved



