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!)
A337752 a(n) is the smallest Moran number m for which m/digsum(m) = prime(n) or 0 if no such number exists. 1

%I #27 Sep 08 2022 08:46:25

%S 18,27,45,21,198,117,153,114,207,261,372,111,738,516,423,954,531,732,

%T 201,1278,511,711,1494,801,1164,1818,1236,1926,1090,1017,1016,2358,

%U 1233,1251,1341,1812,1413,1141,1503,0,1611,1810,3438,2316,3546,3184,2532,2007

%N a(n) is the smallest Moran number m for which m/digsum(m) = prime(n) or 0 if no such number exists.

%C If prime(k) is in A130338 then a(k) = 0.

%H David A. Corneth, <a href="/A337752/b337752.txt">Table of n, a(n) for n = 1..20000</a>

%e A001101(1) = 18 and 18 / digsum(18) = 18/9 = 2 = prime(1), so a(1) = 18.

%e A001101(2) = 21 and 21 / digsum(21) = 21/3 = 7 = prime(4), so a(4) = 21.

%e A001101(3) = 27 and 27 / digsum(27) = 27/9 = 3 = prime(2), so a(2) = 27.

%e A001101(5) = 45 and 45 / digsum(45) = 45/9 = 5 = prime(3), so a(3) = 45.

%e A130338(1) = 173 = prime(40), so a(40) = 0.

%o (Magma) f:=func<n,m| m mod &+Intseq(m) eq 0 and (m div &+Intseq(m) eq NthPrime(n))>; a:=[]; for n in [1..50] do m:=NthPrime(n); while m le 9*NthPrime(n)*(Log(10,m)+1) and not f(n,m) do m:=m+NthPrime(n); end while; if (m div &+Intseq(m) eq NthPrime(n)) then Append(~a,m); else Append(~a,0); end if; end for; a;

%Y Cf. A001101 (Moran numbers), A007953 (digsum), A130338.

%K nonn,base

%O 1,1

%A _Marius A. Burtea_, Sep 18 2020

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 August 24 17:10 EDT 2024. Contains 375417 sequences. (Running on oeis4.)