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A072955
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Suburban numbers: without b, r, s or u.
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1
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1, 2, 5, 8, 9, 10, 11, 12, 15, 18, 19, 20, 21, 22, 25, 28, 29, 50, 51, 52, 55, 58, 59, 80, 81, 82, 85, 88, 89, 90, 91, 92, 95, 98, 99, 1000000, 1000001, 1000002, 1000005, 1000008, 1000009, 1000010, 1000011, 1000012, 1000015, 1000018, 1000019, 1000020
(list;
graph;
refs;
listen;
history;
text;
internal format)
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OFFSET
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1,2
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REFERENCES
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M. J. Halm, Sequences (Re)discovered, Mpossibilities 81 (Aug. 2002).
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LINKS
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PROG
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(Python)
from num2words import num2words
from itertools import islice, product
def ok(n): return set(num2words(n)) & {"b", "r", "s", "u"} == set()
def agen(): # generator of terms < 10**304
base, pows = [k for k in range(1, 1000) if ok(k)], [1]
yield from ([0] if ok(0) else []) + base
for e in range(3, 304, 3):
if set(num2words(10**e)[4:]) & {"b", "r", "s", "u"} == set():
pows = [10**e] + pows
for t in product([0] + base, repeat=len(pows)):
if t[0] == 0: continue
yield sum(t[i]*pows[i] for i in range(len(t)))
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CROSSREFS
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KEYWORD
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easy,nonn,word
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AUTHOR
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STATUS
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approved
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