A222816 Numbers k that divide the base-5 reversal of k.

8, 48, 144, 208, 248, 744, 1008, 1248, 3744, 5008, 5208, 6048, 6248, 18744, 25008, 26208, 30048, 31248, 90144, 93744, 125008, 126008, 130208, 131208, 150048, 151048, 155248, 156248, 450144, 468744, 625008, 631008, 650208, 656208, 750048, 756048, 775248, 781248

Offset: 1

Author

N. J. A. Sloane, Mar 13 2013

Keywords

• nonn
• base

Comments

The base-B reversal of k is obtained by writing k in base B and reversing the order of the digits.

Examples

			8 in base 5 is 13_5; its reverse is 31_5, which is 16 in base 10, and 8 divides 16, so 8 is in the sequence.
		

Links

• N. J. A. Sloane, Table of n, a(n) for n = 1..57
• Leonard F. Klosinski and Dennis C. Smolarski, On the Reversing of Digits, Math. Mag., 42 (1969), 208-210. [Gives a(1)]
• N. J. A. Sloane, 2178 And All That, arXiv:1307.0453 [math.NT], 2013; Fib. Quart., 52 (2014), 99-120.
• N. J. A. Sloane, 2178 And All That [Local copy]

Crossrefs

Cf. A214927, A091079.

Programs

Mathematica

Select[Range[10^6],Divisible[s=FromDigits[Reverse@IntegerDigits[#,5],5],#]&&s!=#&] (* Giorgos Kalogeropoulos, Aug 20 2021 *)

PARI

isok(n) = (rdn = subst(Polrev(digits(n,  5)), x, 5)) && (rdn != n) && (rdn % n) == 0; \\ Michel Marcus, Oct 10 2014

Extensions

More terms from Alois P. Heinz, Mar 13 2013