A090180 - OEIS

%I #6 Nov 21 2013 12:48:16

%S 2,3,23,61,131,151,331,601,661,1013,1033,1103,1123,1231,1237,1259,

%T 1307,1321,1811,2131,2621,2861,3301,4021,4159,4373,4463,4733,4759,

%U 4801,5059,5101,6151,6229,6397,6737,7079,7369,7433,8191,9109,10181,10691,11119

%N Primes p = prime(n) such that p + sum-of-digits(p) +- 1 = prime(n+1).

%H Harvey P. Dale, <a href="/A090180/b090180.txt">Table of n, a(n) for n = 1..1000</a>

%e a(2)=23. S(d)=5. 23+5=28. 28+1=29, the next prime in sequence. a(3)=61. S(d)=7. 61+7=68. 68-1=67, the next prime in sequence.

%t ppQ[n_]:=Module[{sidn=Total[IntegerDigits[n[[1]]]]},n[[1]]+sidn+1 == n[[2]]||n[[1]]+sidn-1==n[[2]]]; Transpose[Select[Partition[Prime[ Range[1500]],2,1],ppQ]][[1]] (* _Harvey P. Dale_, Mar 19 2012 *)

%Y Cf. A089323.

%K easy,nonn,base

%O 1,1

%A _Enoch Haga_, Jan 19 2004