OFFSET
0,3
COMMENTS
In the discussion of A354602, Andrey Zabolotskiy asked what the values of the sequence would be if expressed in terms of a and b. This sequence lists these values.
LINKS
PROG
(SageMath)
B.<s1, s2> = BraidGroup(3)
gen = [s1*s2*s1, s1*s2]
gen += [x^-1 for x in gen]
e = B(())
words, a = {e: 1}, [1]
for n in range(15):
old_words, words = words, {}
for w, c in old_words.items():
for g in gen:
nw = w*g
words[nw] = words.get(nw, 0) + c
a.append(words.get(e, 0))
print(a) # Andrey Zabolotskiy, Jan 16 2024
CROSSREFS
KEYWORD
nonn,more
AUTHOR
Alexei Vernitski, Nov 25 2022
EXTENSIONS
a(11)-a(14) from Andrey Zabolotskiy, Jan 16 2024
STATUS
approved