A090180 - OEIS

A090180

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

2, 3, 23, 61, 131, 151, 331, 601, 661, 1013, 1033, 1103, 1123, 1231, 1237, 1259, 1307, 1321, 1811, 2131, 2621, 2861, 3301, 4021, 4159, 4373, 4463, 4733, 4759, 4801, 5059, 5101, 6151, 6229, 6397, 6737, 7079, 7369, 7433, 8191, 9109, 10181, 10691, 11119

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

OFFSET

1,1

LINKS

Harvey P. Dale, Table of n, a(n) for n = 1..1000

EXAMPLE

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.

MATHEMATICA

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 *)

CROSSREFS

Cf. A089323.

Sequence in context: A041787 A143853 A195241 * A350523 A262730 A260127

Adjacent sequences: A090177 A090178 A090179 * A090181 A090182 A090183

KEYWORD

easy,nonn,base

AUTHOR

Enoch Haga, Jan 19 2004

STATUS

approved