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A261173 Table read by antidiagonals: T(n,k) = smallest prime p containing only digits 0 and 1 with n 0's and k 1's, or 0 if no such p exists. 1

%I #18 Apr 05 2020 22:26:53

%S 11,0,101,0,0,0,0,10111,0,0,0,101111,0,0,0,0,0,0,1011001,0,0,0,

%T 11110111,0,10011101,10010101,0,0,0,101111111,101101111,0,100100111,

%U 101001001,0,0,0,0,1010111111,1001110111,0,1000011011,1000001011,0,0

%N Table read by antidiagonals: T(n,k) = smallest prime p containing only digits 0 and 1 with n 0's and k 1's, or 0 if no such p exists.

%C T(n, k) = 0 if k is a term of A008585.

%C T(0, k) != 0 iff k is a term of A004023.

%C T(1, k) = A157709(k-2) for all k >= 4.

%C T(n, 2) != 0 iff A062397(n+1) is prime.

%C a(n) is in A168586 iff it is the smallest p in T with A007953(p) = k.

%H Alois P. Heinz, <a href="/A261173/b261173.txt">Antidiagonals n = 0..20, flattened</a>

%e Table T(n, k) starts

%e k = 2 3 4 5

%e -------------------------------------

%e n = 0 | 11 0 0 0

%e n = 1 | 101 0 10111 101111

%e n = 2 | 0 0 0 0

%e n = 3 | 0 0 1011001 10011101

%o (PARI) a(n, k) = i=0; forprime(p=10^(n+k-1), (10^(n+k)-1)/9, if(vecmax(digits(p))==1 && sumdigits(p)==k, return(p); i++; break)); if(i==0, return(0))

%o table(row, col) = for(x=0, row, for(y=2, col, print1(a(x, y), " ")); print(""))

%o table(4, 5) \\ print 5 X 4 table

%Y Cf. A020449, A036929.

%K nonn,tabl,base

%O 0,1

%A _Felix Fröhlich_, Aug 10 2015

%E More terms from _Alois P. Heinz_, Aug 17 2015

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Last modified April 19 16:52 EDT 2024. Contains 371794 sequences. (Running on oeis4.)