A202129 Numbers n such that 90n + 71 is prime.

0, 2, 4, 5, 7, 9, 10, 11, 12, 16, 17, 20, 23, 26, 28, 31, 33, 35, 38, 39, 40, 41, 42, 46, 48, 49, 52, 54, 55, 59, 60, 62, 63, 66, 67, 72, 76, 77, 82, 83, 87, 89, 90, 101, 103, 104, 105, 108, 111, 112, 114, 117, 118, 119, 125, 126, 129, 133, 137, 138, 140

Offset

1,2

Comments

This sequence was generated by adding 12 Fibonacci-like sequences [See: PROG?]. Looking at the format 90n+71 modulo 9 and modulo 10 we see that all entries of A142325 have digital root 8 and last digit 1. (Reverting the process is an application of the Chinese remainder theorem.) The 12 Fibonacci-like sequences are generated (via the p and q "seed" values entered into the Perl program) from the base p,q pairs 71*91, 19*89, 37*53, 73*13, 11*31, 29*49, 47*13, 83*67, 23*7, 41*61, 59*79, 77*43.

Links

Table of n, a(n) for n=1..61.

Mathematica

Select[Range[0, 200], PrimeQ[90 # + 71] &]

Prog

(PARI) is(n)=isprime(90*n+71) \\ Charles R Greathouse IV, Jun 13 2017

Crossrefs

Cf. A181732, A198382, A195993, A196000, A196007, A201739, A201734, A201804, A201816, A201817, A201818, A201820, A201822, A202101, A202104, A202105, A202110, A202112, A202113, A202114, A202115, A202116.

Sequence in context: A140204 A353926 A084577 * A288217 A026457 A185598

Adjacent sequences: A202126 A202127 A202128 * A202130 A202131 A202132

Keyword

nonn,easy

Author

J. W. Helkenberg, Dec 11 2011

Status

approved