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A066146 Primes associated with A066042. 2
2, 37, 2, 2, 571, 47, 3, 3, 103, 61, 113, 97, 797, 41893, 499, 109, 701, 997, 1231, 47, 1801, 557, 1129, 7481, 15731, 32579, 491, 257, 23, 24551, 8753, 110339, 3119, 10133, 46811, 4799, 5233, 215389, 1049, 1063039, 64327, 349, 2477, 69827, 317, 107377 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

No further terms found to 10^8.

LINKS

Harry J. Smith, Table of n, a(n) for n = 1..54

FORMULA

Sum digits of n; find product of digits of n; multiply sum by product; divide this product into n; if result is prime add to sequence

EXAMPLE

a(5)=571 because 4+1+1+1+2=9 and 4*2=8; 8*9=72; 41112/72 = 571 and 571 is prime. [corrected by Harry J. Smith, Feb 02 2010]

MATHEMATICA

rp[n_]:=Module[{idn=IntegerDigits[n], p}, If[MemberQ[idn, 0], p=1, p=n/ (Total[ idn] Times@@idn)]; If[PrimeQ[p], p, 0]]; DeleteCases[ rp/@ Range[ 10^8], 0] (* Harvey P. Dale, Jan 03 2015 *)

PROG

(PARI) ProdD(x)= { local(p=1); while (x>9 && p>0, p*=x%10; x\=10); return(p*x) } SumD(x)= { local(s=0); while (x>9, s+=x%10; x\=10); return(s + x) } { n=0; for (m=1, 10^12, p=ProdD(m); if (p == 0, next); f=m/(SumD(m)*p); if (frac(f)==0 && isprime(f), write("b066146.txt", n++, " ", f); if (n==54, return)) ) } \\ Harry J. Smith, Feb 02 2010

CROSSREFS

Cf. A066042.

Sequence in context: A078081 A077772 A083150 * A258035 A178200 A049106

Adjacent sequences:  A066143 A066144 A066145 * A066147 A066148 A066149

KEYWORD

easy,nonn,base

AUTHOR

Enoch Haga, Dec 13 2001

EXTENSIONS

Offset changed from 2 to 1 by Harry J. Smith, Feb 02 2010

a(32)-a(46) from Harry J. Smith, Feb 02 2010

STATUS

approved

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Last modified October 16 12:23 EDT 2021. Contains 348041 sequences. (Running on oeis4.)