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A084979 Palindromes such that the product of the digits + 1 is prime. 1
1, 2, 4, 6, 11, 22, 44, 66, 111, 121, 141, 161, 212, 232, 242, 272, 292, 323, 343, 383, 414, 464, 474, 545, 565, 616, 626, 636, 656, 747, 838, 848, 878, 898, 929, 969, 1111, 1221, 1441, 1661, 2112, 2222, 2332, 2552, 2772, 2882, 3223, 3883, 4114, 4444, 4554 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

LINKS

Table of n, a(n) for n=1..51.

FORMULA

a(n) >> n^k, where k = log_3(10) = 2.0959....

EXAMPLE

E.g. 383 is 3*8*3 = 72, 72+1 = 73 is prime.

MATHEMATICA

Select[ Range[4663], FromDigits[ Reverse[ IntegerDigits[ # ]]] == # && PrimeQ[1 + Times @@ IntegerDigits[ # ]] & ]

CROSSREFS

Cf. A081988.

Sequence in context: A096460 A322051 A084353 * A049914 A056763 A190071

Adjacent sequences:  A084976 A084977 A084978 * A084980 A084981 A084982

KEYWORD

nonn,base

AUTHOR

Meenakshi Srikanth (menakan_s(AT)yahoo.com), Jun 21 2003

EXTENSIONS

Edited, corrected and extended by Robert G. Wilson v, Jun 21 2003

Formula by Charles R Greathouse IV, Aug 02 2010

STATUS

approved

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Last modified April 17 16:59 EDT 2021. Contains 343063 sequences. (Running on oeis4.)