A145714 a(n) = ceiling(sqrt(2*A145701(n))).

3, 5, 6, 11, 12, 19, 25, 29, 42, 48, 65, 72, 79, 84, 90, 101, 174, 204, 205, 209, 221, 245, 264, 275, 289, 299, 306, 349, 371, 372, 408, 409, 415, 449, 456, 474, 521, 535, 546, 569, 571, 575, 594

Offset: 1

Author

Vladimir Shevelev, Oct 16 2008

Keywords

• nonn

Comments

If p_n is the n-th prime, then ceiling(sqrt(2p_n)) is in the sequence iff A145236(n) = A145236(n+1).

Crossrefs

Cf. A145236, A145701.

Programs

Maple

A145701 :=proc(n) local p; if n = 1 then return 3; end if; p := nextprime(procname(n-1)) ; while true do if isprime(p) and isprime(p+2) then if floor(sqrt(2*p)) <> floor( sqrt(2*p+4)) then return p; end if; end if; p := nextprime(p) ; end do; end proc:
A145714 := proc(n) ceil(sqrt(2*A145701(n))) ; end proc:
for n from 1 to 80 do printf("%d,\n",A145714(n)) ; end do; # R. J. Mathar, Aug 02 2010

Extensions

More terms from R. J. Mathar, Aug 02 2010