A244547 Numbers k with nonzero digits such that k +/- the product of digits of k are both palindromes.
1, 2, 3, 4, 247, 252, 348, 843, 15451, 25152, 25252, 25352, 25452, 36563, 36968, 44594, 51165, 51415, 52125, 52225, 52325, 52425, 63536, 92529, 1455541, 1545451, 1595451, 1954591, 2255522, 2524752, 2525252, 2534852, 2584352, 2853582, 2856582, 3159563, 3354533, 3524753, 3534353
Offset: 1
Examples
247 has all digits > 0. 247 - 2*4*7 = 191 is a palindrome, and 247 + 2*4*7 = 303 is a palindrome. Thus 247 is a member of this sequence.
Programs
-
Mathematica
Select[Range@100000,(p=#+{1,-1}*Times@@IntegerDigits@#; Differences@p!={0}&&AllTrue[p,PalindromeQ])&] (* Hans Rudolf Widmer, Sep 03 2023 *) -
PARI
rev(n)={r="";for(i=1,#digits(n),r=concat(Str(digits(n)[i]),r));return(eval(r))} for(n=1,10^7,dig=digits(n);p=prod(k=1,#dig,dig[k]);if(p!=0,mi=n-p;ma=n+p;if(rev(mi)==mi&&rev(ma)==ma,print1(n,", "))))