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A052022
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Smallest number m larger than prime(n) such that prime(n) = sum of digits of m and prime(n) = largest prime factor of m (or 0 if no such number exists).
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7
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12, 50, 70, 308, 364, 476, 1729, 4784, 9947, 8959, 38998, 588965, 179998, 1879859, 5988788, 38778989, 79693999, 287978998, 1489989599, 4595969989, 6888999949, 45999897788, 197999598599, 3999966997975, 6849998899886, 7885998969988, 35889999789995, 39969896999968
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OFFSET
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2,1
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COMMENTS
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Does there exist a solution for every prime p?
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LINKS
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Table of n, a(n) for n=2..29.
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EXAMPLE
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p=43 -> a(14)=179998 -> 1+7+9+9+9+8 = 43 and 179998 = 2*7*13*23*43. p=47 -> a(15)=1879859 -> 1+8+7+9+8+5+9 = 47 and 1879859 = 23*37*47*47.
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MAPLE
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A052022(n) = {
local( p, m );
p=prime(n) ;
for(k=2, 1000000000,
m=k*p;
if( A007953(m) == p && A006530(m) == p,
return(m) ;
)
) ;
} # R. J. Mathar, Mar 02 2012
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MATHEMATICA
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snm[n_]:=Module[{k=2, p=Prime[n], m}, m=k p; While[Total[ IntegerDigits[ m]]!=p||FactorInteger[m][[-1, 1]]!=p, k++; m=k p]; m]; Array[snm, 18, 2] (* Harvey P. Dale, Feb 28 2012 *)
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CROSSREFS
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Cf. A052018, A052019, A052020, A052021, A007953, A005349, A028834.
Sequence in context: A041274 A029586 A081292 * A110907 A009937 A009932
Adjacent sequences: A052019 A052020 A052021 * A052023 A052024 A052025
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KEYWORD
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nonn,base,nice
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AUTHOR
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Patrick De Geest, Nov 15 1999
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EXTENSIONS
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a(20)-a(29) from Donovan Johnson, May 09 2012
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STATUS
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approved
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