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A229804 Zeroless numbers n such that n and n*product_of_digits(n) are both palindromes. 1
1, 2, 3, 11, 22, 77, 111, 121, 131, 212, 464, 1111, 1221, 2112, 11111, 11211, 11311, 12121, 21112, 22622, 111111, 112211, 121121, 211112, 1111111, 1112111, 1113111, 1121211, 1211121, 2111112, 2223222, 4213124, 11111111, 11122111, 11211211, 12111121, 21111112 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

Palindromes in the sequence A229550.

LINKS

Giovanni Resta, Table of n, a(n) for n = 1..200

EXAMPLE

77*(7*7) = 343*11 = 3773 (another palindrome). So 77 is a member of this sequence.

464*(4*6*4) = 44544 (another palindrome). So, 464 is a member of this sequence.

PROG

(Python)

def pal(n):

..r = ''

..for i in str(n):

....r = i + r

..return r == str(n)

def DP(n):

..p = 1

..for i in str(n):

....p *= int(i)

..return p

{print(n, end=', ') for n in range(1, 10**6) if DP(n)*pal(n)*pal(n*DP(n))}

## Simplified by Derek Orr, Apr 05 2015

(PARI) pal(n)=d=digits(n); Vecrev(d)==d

for(n=1, 10^8, d=digits(n); p=prod(i=1, #d, d[i]); if(p*pal(n)*pal(n*p), print1(n, ", "))) \\ Derek Orr, Apr 05 2015

CROSSREFS

Cf. A229550, A007954.

Sequence in context: A128921 A118595 A229549 * A241096 A057135 A229805

Adjacent sequences:  A229801 A229802 A229803 * A229805 A229806 A229807

KEYWORD

nonn,easy,base

AUTHOR

Derek Orr, Sep 29 2013

STATUS

approved

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Last modified October 16 20:36 EDT 2021. Contains 348047 sequences. (Running on oeis4.)