OFFSET
1,1
LINKS
Alois P. Heinz, Table of n, a(n) for n = 1..10000 (terms n = 1..1000 from T. D. Noe)
MATHEMATICA
t={}; Do[p=Prime[n]; If[Select[Differences[IntegerDigits[p]], #>0&]=={}, AppendTo[t, p]], {n, 460}]; t (* Jayanta Basu, May 04 2013 *)
Select[Prime[Range[600]], Max[Differences[IntegerDigits[#]]]<1&] (* Harvey P. Dale, Oct 30 2013 *)
PROG
(PARI) is(n)=my(d=digits(n)); for(i=2, #d, if(d[i]>d[i-1], return(0))); isprime(n) \\ Charles R Greathouse IV, Aug 18 2017
(Python)
from itertools import count, islice, combinations_with_replacement
from sympy import isprime
def A028867_gen(): # generator of terms
yield from (2, 3, 5, 7)
a, b = {'1':1, '2':1, '3':2, '4':2, '5':2, '6':2, '7':3, '8':3, '9':4}, (1, 3, 7, 9)
for l in count(1):
mlist = []
for d in combinations_with_replacement('987654321', l):
k = 10*int(''.join(d))
for e in b[:a[d[-1]]]:
if isprime(m:=k+e):
mlist.append(m)
yield from sorted(mlist)
CROSSREFS
KEYWORD
nonn,base
AUTHOR
EXTENSIONS
Definition corrected by Omar E. Pol, Mar 22 2012
STATUS
approved