

A053219


Reverse of triangle A053218, read by rows.


3



1, 3, 2, 8, 5, 3, 20, 12, 7, 4, 48, 28, 16, 9, 5, 112, 64, 36, 20, 11, 6, 256, 144, 80, 44, 24, 13, 7, 576, 320, 176, 96, 52, 28, 15, 8, 1280, 704, 384, 208, 112, 60, 32, 17, 9, 2816, 1536, 832, 448, 240, 128, 68, 36, 19, 10, 6144, 3328, 1792, 960, 512, 272, 144, 76, 40
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OFFSET

1,2


COMMENTS

First element in each row gives A001792. Difference between center element of row 2n1 and row sum of row n (A053220(n+4)  A053221(n+4)) gives A045618(n).
Subtriangle of triangle in A062111.  Philippe Deléham, Nov 21 2011
Can be seen as the transform of 1, 2, 3, 4, 5, ... by a variant of the boustrophedon algorithm (see the Sage implementation).  Peter Luschny, Oct 30 2014


LINKS

Table of n, a(n) for n=1..64.


EXAMPLE

Triangle begins:
1
3, 2
8, 5, 3
20, 12, 7, 4
48, 28, 16, 9, 5 ...


MATHEMATICA

Map[Reverse, NestList[FoldList[Plus, #[[1]]+1, #]&, {1}, 10]]//Grid (* Geoffrey Critzer, Jun 27 2013 *)


PROG

(Sage)
def u():
for n in PositiveIntegers():
yield n
def bous_variant(f):
k = 0
am = f.next()
a = [am]
while True:
yield list(a)
am = f.next()
a.append(am)
for m in range(k, 1, 1):
am += a[m]
a[m] = am
k += 1
b = bous_variant(u())
[b.next() for _ in range(8)] # Peter Luschny, Oct 30 2014


CROSSREFS

Cf. A053218 (reverse of this triangle), A053220 (center elements), A053221 (row sums), A001792, A045618, A062111.
Sequence in context: A211164 A097018 A127541 * A173030 A271589 A083087
Adjacent sequences: A053216 A053217 A053218 * A053220 A053221 A053222


KEYWORD

nonn,tabl


AUTHOR

Asher Auel (asher.auel(AT)reed.edu), Jan 01 2000


STATUS

approved



