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A344580
Numbers k such that A101203(k) is prime.
2
4, 5, 6, 7, 8, 15, 18, 19, 26, 33, 44, 50, 64, 69, 74, 115, 138, 139, 150, 151, 161, 170, 208, 213, 218, 232, 233, 237, 246, 258, 275, 289, 290, 303, 309, 310, 311, 333, 334, 340, 352, 353, 360, 369, 376, 405, 412, 441, 483, 489, 495, 502, 503, 507, 514, 529, 610, 615, 633, 638, 645, 648, 658
OFFSET
1,1
COMMENTS
Numbers k such that the sum of nonprimes <= k is prime.
If p is prime then p is a member if and only if p-1 is a member.
LINKS
EXAMPLE
a(3) = 6 is a member because A101203(6) = 1+4+6 = 11 is prime.
MAPLE
s:= proc(n) option remember; if isprime(n) then procname(n-1) else procname(n-1)+ n fi end proc:
s(1):= 1:
select(n -> isprime(s(n)), [$1..1000]);
CROSSREFS
Sequence in context: A050038 A285218 A059709 * A071623 A274552 A280682
KEYWORD
nonn
AUTHOR
J. M. Bergot and Robert Israel, May 23 2021
STATUS
approved