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 A117737 Numbers such that the (positive) difference between the sum of the digits and the product of the digits is a prime number. 1
 20, 24, 25, 27, 29, 30, 33, 34, 35, 37, 38, 42, 43, 45, 47, 49, 50, 52, 53, 54, 56, 57, 59, 65, 67, 70, 72, 73, 74, 75, 76, 78, 79, 83, 87, 92, 94, 95, 97, 101, 102, 104, 106, 110, 111, 112, 113, 114, 115, 116, 117, 118, 119, 120, 121, 125, 126, 128, 131, 133, 140 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 LINKS Robert Israel, Table of n, a(n) for n = 1..10000 EXAMPLE 97 is in the sequence because the sum of its digits is 16, the product of its digits is 63 and the difference between 16 and 63 is 47, which is a prime. MAPLE filter:= proc(n) local L; L:= convert(n, base, 10); isprime(abs(convert(L, `+`)-convert(L, `*`))) end proc: select(filter, [\$1..1000]); # Robert Israel, Jan 22 2019 MATHEMATICA Select[Range[140], PrimeQ[Abs[Plus@@(x=IntegerDigits[#])-Times@@x]]&] (* Jayanta Basu, May 18 2013 *) PROG (PARI) sudig(i, suOrmul)= { local(nshft, resul) ; nshft = i ; resul = nshft % 10 ; nshft = nshft \ 10 ; while(nshft>0, if(suOrmul==0, resul += nshft % 10, resul *= nshft % 10 ) ; nshft \= 10 ; ) ; return(resul) ; } { for(n=10, 150, summ = sudig(n, 0) ; mull = sudig(n, 1) ; if( isprime(summ-mull), print1(n, ", ") ) ; ) ; } \\ R. J. Mathar, Apr 21 2006 CROSSREFS Cf. A000040. Sequence in context: A199360 A199585 A093716 * A062908 A111323 A250289 Adjacent sequences:  A117734 A117735 A117736 * A117738 A117739 A117740 KEYWORD base,nonn AUTHOR Luc Stevens (lms022(AT)yahoo.com), Apr 14 2006 EXTENSIONS More terms from R. J. Mathar, Apr 21 2006 STATUS approved

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Last modified October 27 05:38 EDT 2020. Contains 338035 sequences. (Running on oeis4.)