A100414 Numbers n such that n is R(n)-th composite number where R(n) is the digit reversal of n (A002808(A004086(n))=n).

21, 48034, 69926, 180461, 214591, 409473, 563715, 41630193, 253385633342, 661494322636

Offset: 1

Author

Farideh Firoozbakht, Dec 10 2004

Keywords

• base
• more
• nonn

Comments

There is no further term < 3*10^9.

a(11) > 3*10^12. [Donovan Johnson, Jun 14 2009]

Examples

			41630193 is in the sequence because 41630193 is the 39103614th composite number.
		

Crossrefs

Cf. A002808, A004086, A100412, A100413, A100415.

Programs

Mathematica

Do[s=FromDigits[Reverse[IntegerDigits[n]]];If[s
				

Extensions

a(9)-a(10) from Donovan Johnson, Jun 14 2009