OFFSET
1,4
LINKS
Muniru A Asiru, Table of n, a(n) for n = 1..1000
FORMULA
a(n) = prime(n) mod (prime(n+1) - prime(n)) where prime(n) is the n-th prime.
EXAMPLE
7 is followed by 11. 7 mod (11-7) = 7 mod 4 = 3. So a(4) = 3.
This residue is always odd: 3 = 1*2 + 1, 7 = 1*4 + 3, 23 = 3*6 + 5, etc.
MAPLE
seq(ithprime(i) mod (ithprime(i+1)-ithprime(i)), i=1..2000); # Muniru A Asiru, Jan 29 2018
MATHEMATICA
Table[Mod[Prime[n], Prime[n+1] - Prime[n]], {n, 1, 100}] (* Vincenzo Librandi, Jan 29 2018 *)
PROG
(PARI) a(n) = prime(n) % (prime(n+1) - prime(n)); \\ Michel Marcus, Nov 26 2013
(GAP) P:=Filtered([1..10^7], IsPrime);;
P1:=List([1..Length(P)-1], n -> P[n+1] - P[n]);;
A060234 := List([1..Length(P1)], n->P[n] mod P1[n]); # Muniru A Asiru, Jan 29 2018
(Magma) [NthPrime(n) mod (NthPrime(n+1)-NthPrime(n)): n in [1..100]]; // Vincenzo Librandi, Jan 29 2018
CROSSREFS
KEYWORD
nonn
AUTHOR
Labos Elemer, Mar 21 2001
STATUS
approved