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A263483
a(n) = prime(n)+(prime(n) modulo 6).
1
4, 6, 10, 8, 16, 14, 22, 20, 28, 34, 32, 38, 46, 44, 52, 58, 64, 62, 68, 76, 74, 80, 88, 94, 98, 106, 104, 112, 110, 118, 128, 136, 142, 140, 154, 152, 158, 164, 172, 178, 184, 182, 196, 194, 202, 200, 212, 224, 232, 230, 238, 244, 242, 256, 262, 268, 274, 272, 278, 286, 284, 298, 308, 316, 314
OFFSET
1,1
COMMENTS
For n>2, a(n)-a(n+1)=2 iff prime(n) and prime(n+1) are twin primes; e.g., a(3)-a(4)=10-8=2 and prime(3)=5 and prime(4)=7 are twin primes.
LINKS
FORMULA
a(n) = A000040(n) + A039704(n). - Michel Marcus, Oct 27 2015
MAPLE
p:= 1:
for n from 1 to 100 do
p:= nextprime(p);
A[n]:= p + (p mod 6);
od:
seq(A[n], n=1..100); # Robert Israel, Jul 18 2018
MATHEMATICA
Table[(p=Prime[n])+Mod[p, 6], {n, 100}]
PROG
(PARI) a(n) = apply(x->(x + x%6), prime(n)); \\ Michel Marcus, Oct 27 2015
CROSSREFS
Sequence in context: A028279 A114743 A089546 * A363700 A249982 A292767
KEYWORD
nonn
AUTHOR
Zak Seidov, Oct 19 2015
STATUS
approved