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A051640
a(n) contains the digit b-1 in all bases b from 2 to n.
2
1, 2, 7, 14, 23, 47, 47, 239, 239, 239, 239, 5927, 13679, 13679, 13679, 57119, 159119, 500399, 500399, 1627919, 2585519, 3694397, 7305479, 17067599, 41126399, 41126399, 41126399, 61483967, 586370399, 589188599, 1278033119, 1278033119, 1278033119, 1278033119, 1278033119
OFFSET
2,2
EXAMPLE
47 = 101111 (base 2), 1202 (base 3), 233 (base 4), 142 (base 5), 115 (base 6), 65 (base 7), 57 (base 8). Base 2 representation contains digit 1, base 3 representation contains digit 2, base 4 representation contains digit 3, etc., so a(8)=47.
PROG
(Python)
from sympy.ntheory.factor_ import digits
def A051640(n):
m = 0
while True:
for b in range(2, n+1):
if b-1 not in digits(m, b)[1:]:
break
else:
return m
m += 1 # Chai Wah Wu, May 18 2020
CROSSREFS
Sequence in context: A249852 A324587 A018392 * A119354 A249547 A088207
KEYWORD
base,nonn,nice
AUTHOR
Jeff Burch, Jun 04 2000
EXTENSIONS
More terms from Ulrich Schimke (ulrschimke(AT)aol.com), Jun 12 2000
Definition corrected by Franklin T. Adams-Watters, Apr 10 2006
a(34)-a(36) from Chai Wah Wu, May 18 2020
STATUS
approved

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Last modified September 20 16:00 EDT 2024. Contains 376073 sequences. (Running on oeis4.)