A048343 Total number of distinct palindromes of form 'n-digit number' x 'n-digit number_reversed' (n-digit number not palindromic).

0, 1, 3, 10, 19, 44, 86, 171, 308, 551, 920

Offset: 1

Author

Patrick De Geest, Feb 15 1999

Keywords

• nonn
• base
• more

Examples

			E.g., 3 solutions for 3-digit numbers: 102 * 201 = 20502; 112 * 211 = 23632; 122 * 221 = 26962.
		

Links

• P. De Geest, Palindromic Products of Non Palindromic Integers and their Reversals

Crossrefs

Cf. A048344.

Programs

Python

def A048343(n):
    y, plist = 0, []
    for i in range(10**(n-1),10**n):
        s1 = str(i)
        s2 = s1[::-1]
        if s1 != s2:
            p = i*int(s2)
            if not p in plist:
                sp = str(p)
                if sp == sp[::-1]:
                    plist.append(p)
                    y += 1
    return y # Chai Wah Wu, Sep 05 2014

Extensions

More terms from Sam Handler (sam_5_5_5_0(AT)yahoo.com), Aug 18 2006

Offset changed and two terms added by Lars Blomberg, Nov 25 2011