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A118559 Lucky numbers for which both the sum of the digits and the product of the digits is also a lucky number. 1
1, 3, 7, 9, 111, 133, 135, 171, 331, 357, 535, 537, 553, 717, 735, 11113, 11137, 11173, 11371, 11373, 11535, 11731, 11911, 13113, 13117, 13179, 13317, 13335, 13371, 13515, 13533, 13551, 15333, 15511, 15531, 17313, 17391, 17737, 17913, 17997 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,2
LINKS
EXAMPLE
133 is in the sequence because: (1) it is a lucky number, (2) the sum of its digits 1+3+3=7 is a lucky number, (3) the product of its digits 1*3*3=9 is a lucky number.
MATHEMATICA
lst = Range[1, 19172, 2]; i = 2; While[ i <= (len = Length@lst) && (k = lst[[i]]) <= len, lst = Drop[lst, {k, len, k}]; i++ ]; Select[lst, MemberQ[lst, Plus @@ IntegerDigits@# ] && MemberQ[lst, Times @@ IntegerDigits@# ] &] (* Robert G. Wilson v *)
CROSSREFS
Sequence in context: A363572 A337613 A152607 * A189244 A127789 A112105
KEYWORD
base,nonn
AUTHOR
Luc Stevens (lms022(AT)yahoo.com), May 07 2006
EXTENSIONS
Corrected and extended by Adam Panagos (adam.panagos(AT)gmail.com) and Robert G. Wilson v, May 10 2006
STATUS
approved

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Last modified May 22 04:07 EDT 2024. Contains 372742 sequences. (Running on oeis4.)