A244542 - OEIS

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A244542

Palindromes n such that n +/- the product of digits of n are both palindromes.

1, 2, 3, 4, 101, 202, 252, 303, 404, 505, 606, 707, 808, 909, 1001, 2002, 3003, 4004, 5005, 6006, 7007, 8008, 9009, 10001, 10101, 10201, 10301, 10401, 10501, 10601, 10701, 10801, 10901, 11011, 12021, 13031, 14041, 15051, 15451, 16061, 17071, 18081, 19091, 20002, 20102, 20202

(list; graph; refs; listen; history; text; internal format)

OFFSET

1,2

COMMENTS

These are the palindromes in A244541.

All palindromes with a zero will be in this sequence.

The palindromes that do not contain a zero but do satisfy the definition begin 1, 2, 3, 4, 252, 15451, 25152, 25252, 25352, 25452, 36563, 51415, 52125, 52225, 52325, 52425, 63536, 92529, 1455541, 1545451, 1954591 . . . - Harvey P. Dale, May 14 2019

LINKS

Table of n, a(n) for n=1..46.

EXAMPLE

101 - 1*0*1 and 101 + 1*0*1 are both palindromes (still 101). So 101 is a member of this sequence.

PROG

(PARI) rev(n)={r=""; for(i=1, #digits(n), r=concat(Str(digits(n)[i]), r)); return(eval(r))}

for(n=1, 10^5, if(rev(n)==n, dig=digits(n); p=prod(k=1, #dig, dig[k]); mi=n-p; ma=n+p; if(rev(mi)==mi&&rev(ma)==ma, print1(n, ", "))))

CROSSREFS

Cf. A007954, A244541.

Sequence in context: A262526 A171564 A244541 * A085935 A100981 A001095

Adjacent sequences: A244539 A244540 A244541 * A244543 A244544 A244545

KEYWORD

nonn,base

AUTHOR

Derek Orr, Jun 29 2014

STATUS

approved