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A038364
Numbers n such that n = (product of digits of n) + (sum of digits of n).
9
0, 19, 29, 39, 49, 59, 69, 79, 89, 99
OFFSET
1,2
COMMENTS
A number n with m digits belongs to the sequence if K1*K2*K3*...*Km-9_(m-1)*K1-9_(m-2)*K2....=0 where Ki are the digits of n and 9_(m-1) is a repdigit with 9 repeated (m-1) times. Hence m=2, so sequence is complete.
MAPLE
select(proc(t) local d; d:= convert(t, base, 10); convert(d, `+`)+convert(d, `*`)=t end proc, [$0..100]); # Robert Israel, Dec 16 2014
MATHEMATICA
Select[Range[100], # == Times @@ IntegerDigits[#] + Plus @@ IntegerDigits[#] &] (* Michael De Vlieger, Dec 26 2014 *)
PROG
(PARI) isok(n) = my(d=digits(n)); n == (sum(i=1, #d, d[i]) + prod(i=1, #d, d[i])); \\ Michel Marcus, Apr 06 2014
CROSSREFS
Sequence in context: A061763 A088474 A087097 * A151360 A329106 A109276
KEYWORD
fini,nonn,base,full
AUTHOR
STATUS
approved