A228628 9's complement of prime(n).

7, 6, 4, 2, 88, 86, 82, 80, 76, 70, 68, 62, 58, 56, 52, 46, 40, 38, 32, 28, 26, 20, 16, 10, 2, 898, 896, 892, 890, 886, 872, 868, 862, 860, 850, 848, 842, 836, 832, 826, 820, 818, 808, 806, 802, 800, 788, 776, 772, 770, 766, 760, 758, 748, 742, 736, 730, 728

Offset: 1

Author

Michel Lagneau, Aug 28 2013

Keywords

• nonn
• base
• easy

Comments

a(n) = 10^k - 1 - prime(n) where k is the number of digits in prime(n). If d is d digit in prime(n) replace it with 9 - d.

Examples

			a(6) = 86 because prime(6) = 13 and 9 - 1 = 8, 9 - 6 = 3.
		

Links

• Charles R Greathouse IV, Table of n, a(n) for n = 1..10000

Crossrefs

Cf. A000040, A061601, A160668.

Programs

Maple

a:= n-> (p-> 10^length(p)-p-1)(ithprime(n)):
seq(a(n), n=1..100);  # Alois P. Heinz, Dec 08 2017

Mathematica

nineComplement[n_] := FromDigits[Table[9, {Length[IntegerDigits[Prime[n]]]}] - IntegerDigits[Prime[n]]]; Table[nineComplement[n], {n, 1, 71}]

PARI

a(n)=my(p=prime(n));10^#Str(p)-p-1 \\ Charles R Greathouse IV, Aug 29 2013

Python

from sympy import primerange
def nc(n): return 10**len(str(n)) - 1 - n
def auptop(limit): return [nc(p) for p in primerange(1, limit+1)]
print(auptop(271)) # Michael S. Branicky, Jul 06 2021

Formula

a(n) = A061601(A000040(n)). - Charles R Greathouse IV, Aug 29 2013

a(n) = A160668(n) - 1. Alois P. Heinz, Dec 08 2017