A117059 - OEIS

The OEIS is supported by the many generous donors to the OEIS Foundation.

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).

Other ways to Give

A117059

Palindromes for which the multiplicative digital root is a prime.

2, 3, 5, 7, 121, 131, 151, 171, 232, 474, 535, 575, 666, 929, 999, 3993, 9339, 11211, 11311, 11511, 11711, 12321, 14741, 15351, 15751, 16661, 19291, 19991, 21312, 22722, 23632, 28782, 29392, 32623, 33233, 33933, 35753, 36363, 38383, 39193

(list; graph; refs; listen; history; text; internal format)

OFFSET

1,1

LINKS

Table of n, a(n) for n=1..40.

EXAMPLE

575 is in the sequence because (1) it is a palindrome and (2)the multiplicative digital root is 5, which is a prime.

MATHEMATICA

d[n_] := IntegerDigits[n]; Select[Range[39200], Reverse[y = d[#1]] == y && PrimeQ[NestWhile[Times @@ d[#] &, #1, # > 9 &]] &] (* Jayanta Basu, Jul 13 2013 *)

CROSSREFS

Cf. A002113.

Sequence in context: A046713 A119835 A076609 * A117058 A067173 A357262

Adjacent sequences: A117056 A117057 A117058 * A117060 A117061 A117062

KEYWORD

base,nonn

AUTHOR

Luc Stevens (lms022(AT)yahoo.com), Apr 16 2006

STATUS

approved