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A202104 Numbers n such that 90*n + 41 is prime. 9

%I

%S 0,1,3,4,5,8,10,11,14,16,17,21,23,26,30,33,35,37,38,42,43,44,45,47,49,

%T 52,56,57,58,59,60,61,63,64,66,72,74,75,77,79,81,85,91,94,96,98,99,

%U 100,102,103,105,109,110,113,114,115,127,131,133,134,136,140

%N Numbers n such that 90*n + 41 is prime.

%C This sequence was generated by adding 12 Fibonacci-like sequences [See: PROG]. Looking at the format 90n+41 modulo 9 and modulo 10 we see that all entries of A142333 have digital root 5 and last digit 1. (Reverting the process is an application of the Chinese remainder theorem.) The 12 Fibonacci-like sequences are generated (via the PERL program) from the base pairs 49*91, 19*59, 37*23, 73*77, 11*61, 29*79, 47*43, 83*7, 13*17, 31*71, 49*89, 67*53.

%t Select[Range[0, 200], PrimeQ[90 # + 41] &]

%o (PARI) is(n)=isprime(90*n+41) \\ _Charles R Greathouse IV_, Feb 17 2017

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

%K nonn,easy

%O 1,3

%A _J. W. Helkenberg_, Dec 11 2011

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Last modified July 28 19:33 EDT 2021. Contains 346335 sequences. (Running on oeis4.)