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A212821
Smallest prime p of the form p = 3^n + k, where k has n prime divisors counted with multiplicity.
0
2, 5, 13, 47, 97, 419, 953, 3019, 7457, 20963, 61609, 189947, 557041, 1614803, 4840313, 14430827, 43276097, 129959363, 388862281, 1165669339, 3493338001, 10471887539, 31395739673
OFFSET
0,1
EXAMPLE
a(0) = 2 because 2 = 1 (A001222(1) = 0) + 3^0 = 1 + 1;
a(1) = 5 because 5 = 2 (A001222(2) = 1) + 3^1 = 2 + 3;
a(2) = 13 because 13 = 4 (A001222(4) = 2) + 3^2 = 4 + 9;
a(3) = 47 because 47 = 20 (A001222(20) = 3) + 3^3 = 20 + 27;
a(4) = 97 because 97 = 16 (A001222(16) = 4) + 3^4 = 16 + 81;
a(5) = 419 because 419 = 176 (A001222(176) = 5) + 3^5 = 176 + 243.
PROG
(PARI) for(n=0, 30, p=3^n; k=1; while(1, if(bigomega(k)==n && isprime(p+k), print1(p+k, ", "); break, k++))) \\ Colin Barker, Jun 27 2014
CROSSREFS
Cf. A001222.
Sequence in context: A079573 A360513 A194635 * A067021 A269068 A098716
KEYWORD
nonn
AUTHOR
EXTENSIONS
More terms from Colin Barker, Jun 27 2014
STATUS
approved