A123928 Numbers k such that the sum of the first k primes with the final digit 1 is prime (the number of consecutive prime numbers in A030430 that should be added to obtain A129077(x)).
1, 3, 11, 27, 29, 31, 33, 49, 73, 77, 79, 123, 149, 157, 167, 169, 189, 207, 211, 219, 223, 227, 241, 261, 313, 319, 323, 329, 333, 357, 359, 417, 419, 423, 441, 463, 477, 491, 499, 513, 517, 553, 559, 573, 637, 667, 707, 709, 711, 729, 747, 757, 777, 813, 893
Offset: 1
Examples
a(3)=11 because 11 is the number of consecutive prime numbers in A030430 that must be added to obtain A129077(3).
Links
- Harvey P. Dale, Table of n, a(n) for n = 1..1000
Programs
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Mathematica
Position[Accumulate[Select[Prime[Range[5000]],Mod[#,10]==1&]],?PrimeQ]//Flatten (* _Harvey P. Dale, May 21 2023 *)