OFFSET
0,2
COMMENTS
The map which is applied to primes in A171024.
LINKS
Matthew L. LaSelle, Table of n, a(n) for n = 0..9999 (first 1000 terms from Alois P. Heinz)
FORMULA
Recurrence: a(10*n+i) = 10*a(n)+g(i) for 0 <= i <= 9, where
g(x) = -13/10080*x^9 +43/840*x^8 -611/720*x^7 +457/60*x^6 -57739/1440*x^5 +5007/40*x^4 -62231/280*x^3 +13941/70*x^2 -319/5*x. - Robert Israel, May 13 2014
MAPLE
a:= proc(n) local m, d; d:=irem(n, 10, 'm');
`if`(n=0, 0, parse(cat(a(m), `if`(d in [1, 5], 6-d, d))))
end:
seq(a(n), n=0..99); # Alois P. Heinz, Mar 02 2013
MATHEMATICA
a[n_]:= IntegerDigits[n]/.{1->5, 5->1} // FromDigits; Table[a[n], {n, 0, 80}] (* Vincenzo Librandi, Jul 30 2013 *)
PROG
(PARI) A222222(n, d=[0, 5, 2, 3, 4, 1, 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)
(Haskell)
a222222 = foldl f 0 . map (read . return) . show :: Integer -> Integer
where f v d = 10 * v + if d == 1 || d == 5 then 6 - d else d
-- Reinhard Zumkeller, Jan 29 2014
CROSSREFS
KEYWORD
AUTHOR
M. F. Hasler, Feb 12 2013
STATUS
approved