OFFSET
0,2
COMMENTS
The map which is applied to primes in A171020.
LINKS
Vincenzo Librandi, Table of n, a(n) for n = 0..1000
MATHEMATICA
a[n_]:= IntegerDigits[n]/.{1->4, 4->1} // FromDigits; Table[a[n], {n, 0, 80}] (* Vincenzo Librandi, Jul 29 2013 *)
PROG
(PARI) A222221(n, d=[0, 4, 2, 3, 1, 5, 6, 7, 8, 9])=sum(i=1, #n=digits(n), d[n[i]+1]*10^(#n-i)) \\ gives correct value for n=0 iff d[1]=0, since digits(0)=[] in PARI (v.2.6)
CROSSREFS
KEYWORD
nonn,base,easy
AUTHOR
M. F. Hasler, Feb 12 2013
STATUS
approved