A232268 Numbers n such that reversal (n^3) plus 1 is prime.

1, 3, 4, 6, 10, 19, 28, 30, 31, 40, 60, 63, 64, 66, 87, 88, 93, 96, 100, 129, 132, 135, 138, 141, 144, 184, 190, 274, 279, 280, 283, 285, 292, 294, 297, 300, 303, 310, 393, 399, 400, 402, 433, 436, 439, 589, 597, 598, 600, 612, 616, 621, 628, 630, 639, 640, 642

Offset: 1

Author

K. D. Bajpai, Nov 22 2013

Keywords

• nonn
• base
• less

Comments

If n is a multiple of 10, after reversal leading zeros are discarded before adding 1.

Examples

			a(3)= 4: 4^3= 64: reversing the digits gives 46: 46+1= 47 which is prime.
a(4)= 6: 6^3= 216: reversing the digits gives 612: 612+1= 613 which is prime.
a(12)= 63: 63^3= 250047: reversing the digits gives 740052: 740052+1= 740053 which is prime.
		

Links

• K. D. Bajpai, Table of n, a(n) for n = 1..10000

Crossrefs

Cf. A059008 (numbers n: n^3 reversed is prime).

Cf. A231756 (numbers n: reversal (n^2) plus 1 is prime).

Programs

Maple

with(StringTools): KD:= proc() local a; a:= parse(Reverse(convert((n^3), string)))+1; if isprime(a) then RETURN (n): fi;end: seq(KD(), n=1..5000);

Mathematica

Select[Range[500],PrimeQ[ToExpression[StringReverse[ToString[#^3]]] + 1] &]