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A178855
Partial sums of A033485.
2
1, 3, 6, 11, 18, 28, 41, 59, 82, 112, 149, 196, 253, 323, 406, 507, 626, 768, 933, 1128, 1353, 1615, 1914, 2260, 2653, 3103, 3610, 4187, 4834, 5564, 6377, 7291, 8306, 9440, 10693, 12088, 13625, 15327, 17194, 19256, 21513, 23995, 26702, 29671, 32902, 36432
OFFSET
1,2
LINKS
FORMULA
a(n) = (A033485(2n+1)-1)/2.
MAPLE
b:= proc(n) option remember;
`if`(n<2, n, b(n-1)+b(iquo(n, 2)))
end:
a:= n-> (b(2*n+1)-1)/2:
seq(a(n), n=1..60); # Alois P. Heinz, Feb 17 2022
PROG
(Python)
from itertools import islice
from collections import deque
def A178855_gen(): # generator of terms
aqueue, f, b, a = deque([2]), True, 1, 2
while True:
a += b
aqueue.append(a)
if f:
yield (a-1)//2
b = aqueue.popleft()
f = not f
A178885_list = list(islice(A178855_gen(), 40)) # Chai Wah Wu, Jun 08 2022
CROSSREFS
Sequence in context: A011849 A350104 A173690 * A095944 A014284 A118482
KEYWORD
nonn,easy
AUTHOR
Philippe Deléham, Jun 19 2010
EXTENSIONS
a(40) corrected by Georg Fischer, Aug 28 2020
STATUS
approved