OFFSET
1,2
COMMENTS
These numbers are the possible characteristics of a field.
First differences are in A054541. - Omar E. Pol, Oct 31 2013
Also A158611 without its second term. - Omar E. Pol, Nov 01 2013
The ideals generated by a(n) form Spec(Z), the set of prime ideals of the ring of integers. Due to its importance in algebraic geometry, algebraic geometers often consider 0 to be an honorary prime. - Keith J. Bauer, Jan 09 2024
MATHEMATICA
Prepend[Table[Prime[n], {n, 60}], 0] (* Arkadiusz Wesolowski, Sep 15 2011 *)
NestList[ NextPrime, 0, 57] (* Robert G. Wilson v, Jul 21 2015 *)
PROG
(PARI) a(n)=if(n>1, prime(n-1), 0) \\ Charles R Greathouse IV, Jul 15 2013
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Charles R Greathouse IV, Feb 05 2011
STATUS
approved