A097931 Numbers in base 10 that are palindromic in bases 6 and 7.

0, 1, 2, 3, 4, 5, 92, 135, 178, 185, 5854, 6148, 7703, 186621, 204856, 206620, 213970, 269957, 271721, 279071, 4252232, 160258808, 9689802280, 203509031168, 204191148800, 231773764784, 321015775216, 4102350269485, 12262956787888

Offset: 1

Author

Cino Hilliard, Sep 04 2004

Keywords

• base
• nonn

Comments

Intersection of A029953 and A029954. - Michel Marcus, Oct 09 2014

Examples

			269957 base 10 is 5441445 base 6 and 269957 base 10 is 2203022 base 7.
		

Links

• Giovanni Resta, Table of n, a(n) for n = 1..50 (first 30 terms from Robert G. Wilson v)
• Cino Hilliard, util.gp PARI Functions not in the PARI Library. [broken link]
• Cino Hilliard, Pari Utilities (cached)

Crossrefs

Cf. A029953 (base 6), A029954 (base 7).

Programs

Mathematica

Do[ p6 = IntegerDigits[n, 6]; If[ FromDigits[ Reverse[ p6]] == FromDigits[p6], p7 = IntegerDigits[n, 7]; If[ FromDigits[ Reverse[p7]] == FromDigits[p7], Print[n]]], {n, 10^9}] (* Robert G. Wilson v, Sep 07 2004 *)

PARI

/* Requires reading the util.gp file in the link into the gp session.  */
palbase(n,b1,b2) = { for(x=1,n, if(ispal(base(10,b1,x))& ispal(base(10,b2,x)),print1(x",")) ) }

Extensions

More terms from Robert G. Wilson v, Sep 07 2004

a(23)-a(29) from Donovan Johnson, Apr 23 2010

a(30) from Robert G. Wilson v, Jul 17 2015