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A062998 Numbers whose sum of digits is less than or equal to its product of digits.

%I A062998 #19 Aug 14 2025 09:02:32
%S A062998 1,2,3,4,5,6,7,8,9,22,23,24,25,26,27,28,29,32,33,34,35,36,37,38,39,42,
%T A062998 43,44,45,46,47,48,49,52,53,54,55,56,57,58,59,62,63,64,65,66,67,68,69,
%U A062998 72,73,74,75,76,77,78,79,82,83,84,85,86,87,88,89,92,93,94,95,96,97,98,99,123,124,125,126,127,128,129,132,133,134,135
%N A062998 Numbers whose sum of digits is less than or equal to its product of digits.
%H A062998 Harry J. Smith, <a href="/A062998/b062998.txt">Table of n, a(n) for n = 1..1000</a>
%p A062998 isA062998 := proc(n)
%p A062998         local dgs,s,p ;
%p A062998         dgs := convert(n,base,10) ;
%p A062998         s := add(i,i=dgs) ;
%p A062998         p := mul(i,i=dgs) ;
%p A062998         if s <= p then
%p A062998                 true;
%p A062998         else
%p A062998                 false;
%p A062998         end if;
%p A062998 end proc:
%p A062998 for n from 2 to 150 do
%p A062998         if isA062998(n) then
%p A062998                 printf("%d,",n) ;
%p A062998         end if;
%p A062998 end do:   # _R. J. Mathar_, Aug 14 2025
%t A062998 Select[Range[100],Total[IntegerDigits[#]]<=Times@@IntegerDigits[#]&] (* _Harvey P. Dale_, Feb 21 2017 *)
%o A062998 (PARI) isok(k)={my(d=digits(k)); vecsum(d) <= vecprod(d)} \\ _Harry J. Smith_, Aug 15 2009
%o A062998 (PARI) is_A062998(n)={normlp(n=digits(n),1)<=prod(i=1,#n,n[i])} \\ _M. F. Hasler_, Oct 29 2014
%Y A062998 Cf. A007953, A007954, A034710, A062329, A062996, A062997, A062998, A062999.
%Y A062998 Not the same as A037344 (contains 124).
%K A062998 base,nonn,easy
%O A062998 1,2
%A A062998 _Henry Bottomley_, Jun 29 2001