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A087454
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Multiplicative inverse of the n-th prime p(n) modulo p(n-1).
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2
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1, 2, 3, 2, 6, 10, 9, 5, 4, 15, 26, 28, 21, 11, 8, 9, 30, 51, 17, 36, 61, 20, 14, 78, 73, 51, 26, 54, 82, 105, 32, 22, 69, 14, 75, 126, 131, 41, 28, 29, 90, 163, 96, 145, 99, 83, 88, 56, 114, 172, 39, 120, 217, 42, 43, 44, 135, 226, 208, 141, 85, 21, 77, 156, 235, 68, 276
(list; graph; refs; listen; history; internal format)
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OFFSET
| 2,2
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LINKS
| D. Williams, Multiplicative Inverse mod m [broken link]
Charles R Greathouse IV, Table of n, a(n) for n = 2..10000
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EXAMPLE
| We have a(7) = 10 because prime(7)*10 = 170 = 1 [mod 13] = 1 [mod prime(6)].
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MAPLE
| A087454 := proc(n) local k ; for k from 1 do if modp(k*ithprime(n)-1, ithprime(n-1)) = 0 then return k; end if; end do: end proc: # R. J. Mathar, Aug 23 2011
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PROG
| (PARI) a(n)=my(p=prime(n-1), g=nextprime(p+1)-p); lift(Mod(1/g, p)) \\ Charles R Greathouse IV, Aug 23 2011
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CROSSREFS
| Cf. A069830, A077005.
Sequence in context: A153984 A025502 A110777 * A059446 A188881 A143806
Adjacent sequences: A087451 A087452 A087453 * A087455 A087456 A087457
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KEYWORD
| nonn
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AUTHOR
| Lekraj Beedassy (blekraj(AT)yahoo.com), Oct 23 2003
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EXTENSIONS
| Corrected and extended by Ray Chandler (rayjchandler(AT)sbcglobal.net), Oct 24 2003
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