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A202116 Numbers n such that 90n + 89 is prime. 2
0, 1, 2, 3, 4, 7, 8, 13, 15, 17, 18, 20, 21, 22, 25, 28, 29, 30, 31, 32, 36, 41, 44, 45, 46, 48, 51, 55, 58, 59, 62, 64, 65, 66, 69, 70, 72, 73, 77, 78, 83, 84, 86, 87, 88, 92, 97, 99, 105, 106, 107, 111, 112, 113, 116, 118, 119, 120, 121, 122, 123, 127, 129 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,3

COMMENTS

This sequence was generated by adding 12 Fibonacci-like sequences [See: PROG?]. Looking at the format 90n+89 modulo 9 and modulo 10 we see that all entries of A142335 have digital root 8 and last digit 9. (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 89*91, 19*71, 37*17, 73*53, 11*49, 29*31, 47*67, 83*13, 23*43, 41*79, 59*61, 77*7.

LINKS

Table of n, a(n) for n=1..63.

MATHEMATICA

Select[Range[0, 200], PrimeQ[90 # + 89] &]

PROG

(PARI) is(n)=isprime(90*n+89) \\ Charles R Greathouse IV, Jun 06 2017

CROSSREFS

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

Sequence in context: A301806 A066847 A057887 * A215914 A006049 A084541

Adjacent sequences:  A202113 A202114 A202115 * A202117 A202118 A202119

KEYWORD

nonn,easy

AUTHOR

J. W. Helkenberg, Dec 11 2011

STATUS

approved

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Last modified August 14 19:45 EDT 2020. Contains 336483 sequences. (Running on oeis4.)