A048549
a(n+1) is next smallest prime beginning with a(n), initial prime is 2.
Original entry on oeis.org
2, 23, 233, 2333, 23333, 2333321, 233332117, 2333321173, 233332117313, 23333211731399, 2333321173139903, 2333321173139903173, 23333211731399031733, 2333321173139903173301, 2333321173139903173301021
Offset: 1
Similar to but different from
A069603.
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b = 10; s = {{2}};
Do[NestWhile[# + 1 &, 0, ! (PrimeQ[FromDigits[tmp = Join[Last[s], (nn = #;
IntegerDigits[nn - Sum[b^n, {n, l = NestWhile[# + 1 &, 1, ! (nn - (Sum[b^n, {n, #}]) < 0) &] - 1}], b, l + 1])], b]]) &]; AppendTo[s, tmp], {20}]; Map[FromDigits, s] (* Peter J. C. Moses, Aug 06 2015 *)
A048550
a(n+1) is the next smallest prime beginning with a(n), initial prime is 3.
Original entry on oeis.org
3, 31, 311, 3119, 31193, 3119309, 31193093, 311930933, 31193093317, 311930933179, 3119309331797, 311930933179703, 31193093317970371, 3119309331797037107, 311930933179703710759, 31193093317970371075907
Offset: 0
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f:= proc(n) local d,a;
for d from 1 do
for a from 10^d*n+1 by 2 to 10^d*(n+1) do
if isprime(a) then return a fi
od od
end proc:
R:= 3: x:= 3:
for i from 2 to 30 do
x:= f(x);
R:= R, x;
od:
R; # Robert Israel, Dec 13 2023
A065537
a(n) is smallest prime > 10*a(n-1), a(1) = 7.
Original entry on oeis.org
7, 71, 719, 7193, 71933, 719333, 7193357, 71933597, 719335993, 7193359933, 71933599363, 719335993631, 7193359936331, 71933599363319, 719335993633291, 7193359936332919, 71933599363329217, 719335993633292261
Offset: 1
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NextPrim[n_Integer] := Block[ {k = n + 1}, While[ !PrimeQ[k], k++ ]; Return[k]]; a[1] = 7; a[n_] := NextPrim[ 10*a[n - 1]]; Table[ a[n], {n, 1, 20} ]
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{ for (n=1, 100, if (n>1, a=nextprime(10*a), a=7); write("b065537.txt", n, " ", a) ) } \\ Harry J. Smith, Oct 21 2009
A100895
a(n) = smallest n-digit prime formed by appending a digit to a(n-1); a(1) = 7.
Original entry on oeis.org
7, 71, 719, 7193, 71933, 719333
Offset: 1
a(1)=7
a(2)=71
a(3)=719
a(4)=7193
a(5)=71933
a(6)=719333
Showing 1-4 of 4 results.
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