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Numbers whose sum of digits is less than or equal to its product of digits.
9

%I #13 Dec 05 2024 14:46:13

%S 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 43,44,45,46,47,48,49,52,53,54,55,56,57,58,59,62,63,64,65,66,67,68,69,

%U 72,73,74,75,76,77,78,79,82,83,84,85,86,87,88,89,92,93,94,95,96,97,98

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

%H Harry J. Smith, <a href="/A062998/b062998.txt">Table of n, a(n) for n=1,...,1000</a>

%t Select[Range[100],Total[IntegerDigits[#]]<=Times@@IntegerDigits[#]&] (* _Harvey P. Dale_, Feb 21 2017 *)

%o (PARI) isok(k)={my(d=digits(k)); vecsum(d) <= vecprod(d)} \\ _Harry J. Smith_, Aug 15 2009

%o (PARI) is_A062998(n)={normlp(n=digits(n),1)<=prod(i=1,#n,n[i])} \\ _M. F. Hasler_, Oct 29 2014

%Y Cf. A007953, A007954, A034710, A062329, A062996, A062997, A062998, A062999.

%Y Not the same as A037344 (contains 124).

%K base,nonn,easy

%O 1,2

%A _Henry Bottomley_, Jun 29 2001