

A309899


Numbers k = 1, 2, 3, ... are added to the sequence along with k blanks. Next, the numbers k + 1 are inserted on the blanks along with k + 1 blanks. This process is then repeated.


1



1, 2, 2, 3, 4, 3, 3, 5, 6, 4, 4, 4, 7, 8, 5, 5, 9, 5, 5, 10, 6, 6, 11, 12, 6, 6, 6, 7, 7, 13, 14, 8, 7, 7, 15, 8, 7, 7, 16, 9, 17, 8, 8, 18, 9, 10, 8, 8, 8, 19, 20, 9, 9, 11, 10, 21, 22, 9, 9, 12, 9, 9, 10, 10, 23, 11, 24, 13, 25, 10, 10, 11, 26
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OFFSET

1,2


LINKS

Jan Koornstra, Table of n, a(n) for n = 1..10000


EXAMPLE

The first elements are:
1 _ 2 _ _ 3 _ _ _ 4 _ _ _ _ 5 _ _ _ _ _
2 _ _ 3 _ _ _ 4 _ _ _ _ 5 _ _
3 _ _ _ 4 _ _ _ _ 5 _
4 _ _ _ _ 5 _ _
5 _ _ _ _ _
.
1 2 2 3 4 3 3 5 6 4 4 4 7 8 5 5 9 5 5 10


PROG

(Python)
seq = []
for n in range(1, 100): seq += [n] + n*[1]
for n in range(2, len(seq)):
value = n
gaps = 0
position = n  1
while position < len(seq):
if seq[position] == 1:
if gaps > 0: gaps = 1
else:
seq[position] = value
gaps = value
value += 1
position += 1
print(seq)


CROSSREFS

Cf. A309898, A003602, A002260, A306470.
Sequence in context: A048206 A290740 A075765 * A181024 A214744 A014656
Adjacent sequences: A309896 A309897 A309898 * A309900 A309901 A309902


KEYWORD

nonn,easy


AUTHOR

Jan Koornstra, Aug 21 2019


STATUS

approved



