A202112 - OEIS

%I #13 Jun 01 2016 18:29:56

%S 0,3,4,6,7,11,13,15,17,18,19,20,24,29,33,35,36,38,41,45,46,52,56,57,

%T 60,61,62,63,64,68,70,71,75,81,82,83,84,89,90,91,94,95,96,103,104,106,

%U 111,112,115,119,122,123,124,125,129,130,132,133,137,139,146

%N Numbers n such that 90n + 79 is prime.

%C This sequence was generated by adding 14 Fibonacci-like sequences [See: PROG]. Looking at the format 90n+79 modulo 9 and modulo 10 we see that all entries of A142330 have digital root 7 and last digit 9. (Reverting the process is an application of the Chinese remainder theorem.) The 14 Fibonacci-like sequences are generated (via the p and q values given in the PERL program) from the base p,q pairs 79*91, 19*61, 37*7, 73*43, 11*89, 29*71, 47*17, 83*53, 13*13, 31*49, 67*67, 23*23, 41*59, 77*77.

%F a(n) ~ 24n log n. - _Charles R Greathouse IV_, Jun 01 2016

%t Select[Range[0, 200], PrimeQ[90 # + 79] &]

%o (PARI) is(n)=n%90==79 && isprime(n) \\ _Charles R Greathouse IV_, Jun 01 2016

%Y Cf. A181732, A198382, A195993, A196000, A196007, A201739, A201734, A201804, A201816, A201817, A201818, A201820, A201822, A202101, A202104, A202105, A202110.

%K nonn,easy

%O 1,2

%A _J. W. Helkenberg_, Dec 11 2011