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A175728
Decimal expansion of e written as a sequence of distinct positive integers.
1
2, 7, 1, 8, 28, 18, 284, 5, 90, 4, 52, 3, 53, 60, 287, 47, 13, 526, 6, 24, 9, 77, 57, 2470, 93, 69, 99, 59, 574, 96, 696, 76, 27, 72, 40, 766, 30, 35, 354, 75, 94, 571, 38, 21, 78, 525, 16, 64, 274, 2746, 63, 91, 93200, 305, 992, 181, 74, 135, 966, 290, 43, 572, 900, 33, 42
OFFSET
1,1
COMMENTS
Inverse: 3, 1, 12, 10, 8, 19, 2, 4, 21, 119, 86, 166, 17, 154, 160, 47, 192, 6, 83, 214, ..., . - Robert G. Wilson v, Aug 22 2010
LINKS
MATHEMATICA
rd = RealDigits[E, 10, 200][[1]]; lst = {}; f[n_] := Block[{k = 1}, While[a = FromDigits[ Take[ rd, k]]; MemberQ[lst, a] || rd[[k + 1]] == 0, k++ ]; AppendTo[ lst, a]; rd = Drop[rd, k]]; Array[f, 70]; lst (* Robert G. Wilson v, Aug 22 2010 *)
PROG
(Python)
from itertools import islice
from sympy import exp
def diggen():
yield from map(int, str(exp(1).n(10**5))[:-1].replace(".", ""))
def agen(): # generator of terms
g = diggen()
aset, nextd = set(), next(g)
while True:
an, nextd = nextd, next(g)
while an in aset or nextd == 0:
an, nextd = int(str(an) + str(nextd)), next(g)
yield an
aset.add(an)
print(list(islice(agen(), 65))) # Michael S. Branicky, Mar 31 2022
CROSSREFS
Sequence in context: A282171 A112257 A248684 * A261390 A248676 A369445
KEYWORD
nonn,base
AUTHOR
Jason G. Wurtzel, Aug 19 2010
EXTENSIONS
More terms from Robert G. Wilson v, Aug 22 2010
STATUS
approved