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A253721 Triprimes modulo 10. 3
8, 2, 8, 0, 7, 8, 0, 2, 4, 5, 0, 2, 3, 6, 8, 0, 5, 6, 8, 2, 8, 9, 2, 5, 0, 4, 6, 7, 4, 5, 0, 8, 7, 8, 3, 4, 4, 5, 0, 1, 2, 4, 5, 2, 6, 8, 0, 5, 7, 2, 2, 0, 1, 6, 8, 2, 4, 5, 6, 5, 8, 1, 6, 8, 3, 5, 9, 2, 4, 5, 6, 0, 2, 0, 6, 8, 2, 5, 2, 3, 8, 3, 5, 4, 6, 7 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
COMMENTS
Last digit of triprimes (A014612).
LINKS
FORMULA
a(n) = A010879(A014612(n)). - Michel Marcus, May 03 2015
MAPLE
with(numtheory): A253721:=n->`if`(bigomega(n) = 3, n mod 10, NULL): seq(A253721(n), n=1..500);
MATHEMATICA
Mod[#, 10] & /@ Select[Range[500], PrimeOmega[#] == 3 &]
PROG
(Haskell)
a253721 = flip mod 10 . a014612 -- Reinhard Zumkeller, May 05 2015
(PARI) do(x)=my(v=List(), t); forprime(p=2, x\4, forprime(q=2, min(x\(2*p), p), t=p*q; forprime(r=2, min(x\t, q), listput(v, t*r)))); Set(v)%10 \\ Charles R Greathouse IV, Aug 30 2017
CROSSREFS
Cf. A010879 (final digit of n), A014612 (triprimes).
Cf. A007652 (primes mod 10), A106146 (semiprimes mod 10).
Cf. A255646 (subsequence).
Sequence in context: A134724 A269546 A248299 * A021551 A143025 A303326
KEYWORD
nonn,base,easy
AUTHOR
Wesley Ivan Hurt, May 02 2015
STATUS
approved

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Last modified June 24 03:36 EDT 2024. Contains 373661 sequences. (Running on oeis4.)