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A157529
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Composite numbers whose first digit is equal to the sum of all the other digits.
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1
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22, 33, 44, 55, 66, 77, 88, 99, 110, 202, 220, 303, 312, 321, 330, 404, 413, 422, 440, 505, 514, 532, 550, 606, 615, 624, 633, 642, 651, 660, 707, 716, 725, 734, 752, 770, 808, 817, 826, 835, 844, 862, 871, 880, 909, 918, 927, 936, 945, 954, 963, 972, 981
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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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990 is a composite number whose first digit is equal to the sum of all the other digits.
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MAPLE
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a := proc (n) local nn: nn := convert(n, base, 10): if isprime(n) = false and nn[nops(nn)] = add(nn[j], j = 1 .. nops(nn)-1) then n else end if end proc: seq(a(n), n = 2 .. 1100); # Emeric Deutsch, Mar 07 2009
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CROSSREFS
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KEYWORD
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base,nonn
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AUTHOR
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EXTENSIONS
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STATUS
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approved
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