The OEIS mourns the passing of Jim Simons and is grateful to the Simons Foundation for its support of research in many branches of science, including the OEIS.
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!)
A182174 a(n) = prime(n)^2 - n. 5

%I #27 Sep 08 2022 08:45:55

%S 3,7,22,45,116,163,282,353,520,831,950,1357,1668,1835,2194,2793,3464,

%T 3703,4470,5021,5308,6219,6866,7897,9384,10175,10582,11421,11852,

%U 12739,16098,17129,18736,19287,22166,22765,24612,26531,27850,29889,32000,32719,36438,37205,38764,39555,44474,49681

%N a(n) = prime(n)^2 - n.

%C One way to find a run of n consecutive nonsquarefree numbers such that the first n primes appear in order as factors of numbers in the run is to use the Chinese remainder theorem (though this run is most likely not the earliest of length n).

%C The moduli are then of course the squares of the first n primes, while the remainders are then the first n terms of this sequence. (See A182433.)

%H Vincenzo Librandi, <a href="/A182174/b182174.txt">Table of n, a(n) for n = 1..10000</a>

%F a(n) = A000040(n)^2 - n = A001248(n) - n. - _Omar E. Pol_, Apr 16 2012

%e a(4) = 45 because the 4th prime is 7, and 7^2 - 4 = 49 - 4 = 45.

%t Table[Prime[n]^2 - n, {n, 50}]

%o (Magma) [NthPrime(n)^2-n: n in [1..50]]; // _Bruno Berselli_, Apr 16 2012

%Y Cf. A001248 squares of primes; A045882 and A078144 pertain to runs of consecutive nonsquarefree numbers.

%Y Cf. A014689. [_Bruno Berselli_, Mar 19 2013]

%K nonn,easy

%O 1,1

%A _Alonso del Arte_, Apr 16 2012

%E a(36) inserted by _Vincenzo Librandi_, Mar 19 2013

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 June 4 22:04 EDT 2024. Contains 373102 sequences. (Running on oeis4.)