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A100964
Smallest prime number that begins a prime gap of at least 2n.
4
3, 7, 23, 89, 113, 113, 113, 523, 523, 887, 1129, 1327, 1327, 1327, 1327, 1327, 1327, 9551, 15683, 15683, 15683, 15683, 19609, 19609, 19609, 19609, 31397, 31397, 31397, 31397, 31397, 31397, 31397, 31397, 31397, 31397, 155921, 155921, 155921, 155921
OFFSET
1,1
LINKS
FORMULA
a(n) = prime(A144309(n)). - Michel Marcus, Nov 02 2013
EXAMPLE
a(5) = a(6) = a(7) = 113 because there is a gap of 14 between 113 and 127.
MATHEMATICA
k=1; Table[While[Prime[k+1]-Prime[k] < 2n, k++ ]; Prime[k], {n, 48}]
PROG
(PARI) lista(pmax) = {my(k = 1, prv = 2, m = 2, kprv = 2); forprime(p = 3, pmax, k++; if(p - prv >= m, for(i = 1, (p - prv - m)/2 + 1, print1(prv, ", ")); m = p - prv + 2; kprv = k); prv = p); } \\ Amiram Eldar, Sep 06 2024
CROSSREFS
KEYWORD
nonn
AUTHOR
T. D. Noe, Nov 23 2004
STATUS
approved