login
The OEIS is supported by the many generous donors to the OEIS Foundation.

 

Logo
Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A200088 a(n) is the least number greater than a(n-1) such that the sum of the decimal digits of a(n-1) and a(n) is prime. 0
1, 2, 3, 4, 7, 13, 16, 19, 21, 22, 25, 28, 30, 31, 34, 37, 43, 46, 49, 51, 52, 55, 58, 60, 61, 64, 67, 73, 76, 79, 85, 88, 94, 97, 100, 101, 102, 103, 106, 109, 111, 112, 115, 118, 120, 121, 124, 127, 133, 136, 139, 141, 142, 145, 148, 150, 151, 154, 157 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,2
COMMENTS
Resulting primes: 3, 5, 7, 11, 11, 11, 17, 13, 7, 11, 17, 13, 7, 11, 17, 17, 17, 23, 19, 13, 17, 23, 19, 13, 17, 23, 23, 23, 29, 29, 29, 29, 29.
LINKS
EXAMPLE
a(1)=1, a(2)=2, 1+2=3 prime,
a(5)=7, a(6)=13, 7+1+3=11 prime,
a(6)=13, a(7)=16, 1+3+1+6=11 prime.
MATHEMATICA
t = {1}; Do[nxt = t[[-1]] + 1; While[! PrimeQ[Total[IntegerDigits[t[[-1]]]] + Total[IntegerDigits[nxt]]], nxt++]; AppendTo[t, nxt], {100}]; t (* T. D. Noe, Nov 14 2011 *)
nxt[b_]:=Module[{c=b+1}, While[!PrimeQ[Total[IntegerDigits[b]]+Total[IntegerDigits[c]]], c++]; c]; NestList[nxt, 1, 60] (* Harvey P. Dale, Sep 11 2023 *)
CROSSREFS
Sequence in context: A023162 A022437 A057983 * A004783 A031149 A096723
KEYWORD
nonn,base
AUTHOR
Zak Seidov, Nov 13 2011
EXTENSIONS
Typo in example corrected by Vincenzo Librandi, Nov 13 2011
STATUS
approved

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

License Agreements, Terms of Use, Privacy Policy. .

Last modified February 28 16:50 EST 2024. Contains 370400 sequences. (Running on oeis4.)