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A181518
a(n) is the number for which 2^A181516(n)||(2*a(n))!
2
2, 4, 7, 11, 13, 16, 22, 25, 28, 35, 37, 38, 41, 47, 50, 52, 56, 59, 64, 67, 70, 76, 88, 93, 97, 98, 100, 117, 122, 133, 137, 140, 143, 148, 158, 171, 176, 179, 182, 186, 193, 196, 200, 203, 213, 218, 223, 227, 233, 234, 236, 242, 247, 248, 253, 262, 280, 290, 299
OFFSET
1,1
MAPLE
isA011371 := proc(n) option remember; local k, a; for k from 0 do a := A011371(k) ; if a > n then return false; elif a = n then return true; end if; end do: end proc:
A181516 := proc(n) option remember; local a; if n = 1 then 3; else for a from procname(n-1)+1 do if isprime(a) then if isA011371(a) then return a; end if; end if; end do; end if; end proc:
A181518 := proc(n) for m from 1 do if A011371(m) = A181516(n) then return m/2 ; end if; end do: end proc: # R. J. Mathar, Nov 04 2010
CROSSREFS
Sequence in context: A229618 A087285 A107791 * A262231 A356133 A191323
KEYWORD
nonn
AUTHOR
Vladimir Shevelev, Oct 26 2010
EXTENSIONS
Corrected (88 inserted, 129 replaced by 179) and extended beyond 227 by R. J. Mathar, Nov 04 2010
STATUS
approved