login
This site is supported by donations to The OEIS Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A089824 Primes p such that the next prime after p can be obtained from p by adding the sum of the digits of p. 3
11, 13, 101, 103, 181, 293, 631, 701, 811, 1153, 1171, 1409, 1801, 1933, 2017, 2039, 2053, 2143, 2213, 2521, 2633, 3041, 3089, 3221, 3373, 3391, 3469, 3643, 3739, 4057, 4231, 5153, 5281, 5333, 5449, 5623, 5717, 6053, 6121, 6301, 7043, 7333, 8101, 8543, 9241 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

I call these primes (additive) "pointer primes", in the sense that such primes p "point" to the next prime after p when the sum of the digits of p is added to p.

LINKS

Alois P. Heinz, Table of n, a(n) for n = 1..10000

EXAMPLE

13 + sum of digits of 13 = 17, which is the next prime after 13. Hence 13 belongs to the sequence.

MAPLE

a:= proc(n) option remember; local p, q;

      p:= a(n-1); q:= nextprime(p);

      do p:= q; q:= nextprime(p);

         if add(i, i=convert(p, base, 10))=q-p then break fi

      od; p

    end: a(1):= 11:

seq(a(n), n=1..50);  # Alois P. Heinz, Nov 18 2017

MATHEMATICA

r = {}; Do[p = Prime[i]; q = Prime[i + 1]; If[p + Apply[Plus, IntegerDigits[p]] == q, r = Append[r, p]], {i, 1, 10^6}]; r

Transpose[Select[Partition[Prime[Range[1000]], 2, 1], #[[2]]==#[[1]]+Total[ IntegerDigits[ #[[1]]]]&]][[1]] (* Harvey P. Dale, Apr 20 2013 *)

CROSSREFS

Sequence in context: A056446 A023317 A056436 * A276694 A086549 A108090

Adjacent sequences:  A089821 A089822 A089823 * A089825 A089826 A089827

KEYWORD

base,nonn

AUTHOR

Joseph L. Pe, Jan 09 2004

STATUS

approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified March 21 12:12 EDT 2019. Contains 321369 sequences. (Running on oeis4.)