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A230045
Palindromic primes with strictly increasing sum of digits.
1
2, 3, 5, 7, 181, 191, 373, 383, 727, 757, 787, 797, 17971, 19891, 19991, 76667, 77977, 78887, 79997, 1987891, 1988891, 1998991, 3799973, 3899983, 3998993, 7897987, 7996997, 9888889, 9889889, 9989899, 199999991, 768989867, 779969977, 779999977, 798989897
OFFSET
1,1
COMMENTS
a(1)=2; a(n+1) is the smallest palindromic prime with sum of digits > sum of digits of a(n).
LINKS
Shyam Sunder Gupta, Table of n, a(n) for n = 1..63
EXAMPLE
a(6) = 191, sum of digits is 11; a(7) = 373, sum of digits is 13 and 13 > 11.
MATHEMATICA
a = {}; t = 0; Do[z = n*10^(IntegerLength[n] - 1) + FromDigits@Rest@Reverse@IntegerDigits[n]; If[PrimeQ[z], s = Apply[Plus, IntegerDigits[z]]; If[s > t, t = s; AppendTo[a, z]]], {n, 10^5}]; a
CROSSREFS
Sequence in context: A064155 A230047 A230042 * A069803 A083184 A046478
KEYWORD
nonn,base
AUTHOR
Shyam Sunder Gupta, Oct 06 2013
STATUS
approved