A202101 Numbers k such that 90*k + 59 is prime.

0, 1, 2, 4, 5, 6, 11, 13, 14, 15, 16, 21, 22, 23, 25, 26, 28, 32, 34, 35, 36, 37, 40, 43, 44, 47, 51, 54, 55, 56, 57, 58, 62, 67, 69, 70, 71, 74, 76, 78, 81, 83, 89, 93, 95, 96, 99, 100, 102, 104, 107, 112, 116, 117, 120, 121, 126, 127, 128, 132, 134, 138

Offset: 1

Author

J. W. Helkenberg, Dec 11 2011

Keywords

• nonn
• easy

Comments

This sequence was generated by adding 12 Fibonacci-like sequences [see: PROG]. Looking at 90*n+59 modulo 9 and modulo 10 we see that all entries of A142319 have digital root 5 and last digit 9. (Reverting the process is an application of the Chinese remainder theorem)

Crossrefs

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

Programs

Mathematica

Select[Range[0, 200], PrimeQ[90 # + 59] &]

PARI

is(n)=isprime(90*n+59) \\ Charles R Greathouse IV, Feb 17 2017