A216329 Decades whose prime pattern is the same as the prime pattern in the next decade, with at least one prime.
37, 78, 124, 139, 154, 180, 234, 276, 288, 291, 310, 331, 436, 444, 499, 532, 558, 609, 616, 624, 648, 696, 706, 717, 750, 820, 856, 873, 894, 951, 961, 973, 1047, 1072, 1099, 1114, 1188, 1270, 1309, 1347, 1351, 1356, 1366, 1383, 1414, 1419, 1429, 1447, 1473
Offset: 1
Links
- V. Raman, Table of n, a(n) for n = 1..10000
Programs
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Mathematica
ps0 = {2, 3, 5, 7}; n = 0; t = {}; While[Length[t] < 50, n++; ps1 = Select[Range[10 n, 10 n + 9], PrimeQ]; If[Length[ps0] > 0 && Length[ps0] == Length[ps1] && ps0 + 10 == ps1, AppendTo[t, n - 1]]; ps0 = ps1]; t (* T. D. Noe, Sep 04 2012 *) -
PARI
isok(i) = { isprime(10*i+1)==isprime(10*i+11) && isprime(10*i+3)==isprime(10*i+13) && isprime(10*i+7)==isprime(10*i+17) && isprime(10*i+9)==isprime(10*i+19) && isprime(10*i+1)+isprime(10*i+3)+isprime(10*i+7)+isprime(10*i+9)>=1 } \\ V. Raman, Dec 08 2012
Formula
a(n) >> n log^2 n. - Charles R Greathouse IV, Sep 06 2012