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A048543
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a(n) is the smallest value of m such that A002378(m), the m-th oblong number, contains exactly n 7's.
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11
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8, 108, 878, 870, 8813, 27924, 84129, 882483, 2788865, 7601169, 88190572, 421518419, 4204014483, 26034169427, 42305694389, 88022598108, 546605779129
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graph;
refs;
listen;
history;
text;
internal format)
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OFFSET
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1,1
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LINKS
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EXAMPLE
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From Jesse Sealand, Oct 05 2019: (Start)
a(2) = 108 since A002378(36) = 11772;
a(3) = 878 since A002378(182) = 771762;
a(4) = 870 since A002378(1817) = 757770, etc.
(End).
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PROG
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(Python)
k, m = 1, 2
while True:
if str(m).count('7') == n:
return k
k += 1
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CROSSREFS
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KEYWORD
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nonn,base,more
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AUTHOR
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EXTENSIONS
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STATUS
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approved
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