A171055 -id:A171055 - cp's OEIS frontend

A222251 In the number n, replace all (decimal) digits '6' with '9' and vice versa.

0, 1, 2, 3, 4, 5, 9, 7, 8, 6, 10, 11, 12, 13, 14, 15, 19, 17, 18, 16, 20, 21, 22, 23, 24, 25, 29, 27, 28, 26, 30, 31, 32, 33, 34, 35, 39, 37, 38, 36, 40, 41, 42, 43, 44, 45, 49, 47, 48, 46, 50, 51, 52, 53, 54, 55, 59, 57, 58, 56, 90, 91, 92, 93, 94, 95, 99, 97, 98, 96, 70, 71, 72, 73, 74, 75

Offset: 0

M. F. Hasler, Feb 13 2013

The map which is applied to primes in A171055.

Vincenzo Librandi, Table of n, a(n) for n = 0..1000

Cf. A222210-A222254; A171013-A171016, A175770, A171018-A171057.

a[n_]:= IntegerDigits[n]/.{6->9, 9->6} // FromDigits; Table[a[n], {n, 0, 80}] (* Vincenzo Librandi, Jul 31 2013 *)

A222251(n,d=[0, 1, 2, 3, 4, 5, 9, 7, 8, 6])=sum(i=1,#n=digits(n),d[n[i]+1]*10^(#n-i),!n*d[1]) \\ N.B.: digits(0)=[] in PARI (v.2.6)

def flp69(s): return s.replace("6", "-").replace("9", "6").replace("-", "9")
def aupto(lim): return [int(flp69(s)) for s in map(str, range(lim+1))]
print(aupto(75)) # Michael S. Branicky, Sep 07 2021

A180557 Primes that become a different prime under the mapping 6 <=> 9.

Original entry on oeis.org

67, 97, 163, 167, 193, 197, 263, 293, 367, 397, 461, 491, 563, 593, 607, 641, 647, 653, 661, 677, 683, 907, 941, 947, 953, 977, 983, 991, 1061, 1063, 1091, 1093, 1163, 1193, 1567, 1597, 1601, 1607, 1613, 1663, 1667, 1901, 1907, 1913, 1993, 1997, 2267, 2297

Offset: 1

Zak Seidov and Robert G. Wilson v, Sep 09 2010

Robert Price, Table of n, a(n) for n = 1..2828
Index to Primes, Primes that become a different prime under some mapping.

Cf. A171055, A175791, A180517 thru A180559, A175789, A180560, A180561.

fQ[n_] := Block[{id = IntegerDigits@n}, (MemberQ[id, 6] || MemberQ[id, 9]) && PrimeQ[ FromDigits[ id /. {6 -> 9, 9 -> 6}] ]]; Select[ Prime@ Range@ 350, fQ]

A088999 Flip 6,9 numbers: if number k contains decimal digit '6' or '9', then flip all occurrences of '6' to '9' and vice versa.

Original entry on oeis.org

9, 6, 19, 16, 29, 26, 39, 36, 49, 46, 59, 56, 90, 91, 92, 93, 94, 95, 99, 97, 98, 96, 79, 76, 89, 86, 60, 61, 62, 63, 64, 65, 69, 67, 68, 66, 109, 106, 119, 116, 129, 126, 139, 136, 149, 146, 159, 156, 190, 191, 192, 193, 194, 195, 199, 197, 198, 196, 179, 176, 189

Offset: 1

Cino Hilliard, Nov 02 2003

For digits d of n if d = 6 make it 9 else if d = 9 make it 6.

However, numbers containing neither digit 6 nor 9 are not terms (cf. A222251).

Cf. A171055, A222251.

flip69(n) = { for(x=1,n, y=x; v=0; f=0; ln =length(Str(x)); a = vector(ln); forstep(j=ln,1,-1, r = y%10; a[j]=r; if(r==6,a[j] = 9; f=1); if(r==9,a[j] = 6; f=1); y = floor(y/10); ); forstep(j=ln,1,-1, v=v+a[j]*10^(ln-j) ); if(f,print1(v",")); ) }

def has69(s): return '6' in s or '9' in s
def flp69(s): return s.replace("6", "-").replace("9", "6").replace("-", "9")
def aupto(lim):
    return [int(flp69(s)) for s in map(str, range(lim+1)) if has69(s)]
print(aupto(186)) # Michael S. Branicky, Sep 06 2021

cp's OEIS Frontend

A222251 In the number n, replace all (decimal) digits '6' with '9' and vice versa.

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A180557 Primes that become a different prime under the mapping 6 <=> 9.

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Author

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Programs

Mathematica

A088999 Flip 6,9 numbers: if number k contains decimal digit '6' or '9', then flip all occurrences of '6' to '9' and vice versa.

Views

Author

Keywords

Comments

Crossrefs

Programs

PARI

Python