A274004 First differences of A002960.

3, 3, 4, 5, 5, 6, 6, 7, 7, 8, 9, 9, 10, 10, 11, 11, 12, 12, 13, 13, 14, 14, 15, 15, 16, 17, 17, 18, 18, 19, 19, 20, 20, 21, 21, 22, 22, 23, 23, 24, 24, 25, 25, 26, 26, 27, 27, 28, 28, 29, 29, 30, 30, 31, 31, 32, 33, 33, 34, 34, 35, 35

Offset

1,1

Comments

The squared sieve sequence (A002960) increases by one, beginning with three, every two integers except a difference of 2^n appears only once. This is the sequence of first differences. This has not yet been proven in the general case.

Links

Table of n, a(n) for n=1..62.

Formula

Conjecture: a(n) = A274089(n+2). - Omar E. Pol, Aug 10 2016

Mathematica

Rest@ Differences@ Map[First, NestWhileList[Function[w, {First@ #, Rest@ #} &@ Delete[Last@ w, #] &@ Map[{#} &, Reverse@ Range[Floor@ Sqrt@ Length[Last@ w]]^2]], {0, Range@ 1200}, Length@ Last@ # > 1 &]] (* Michael De Vlieger, Aug 10 2016 *)

Crossrefs

Cf. A002960, A274089.

Sequence in context: A185585 A072945 A307912 * A196592 A120180 A339412

Adjacent sequences: A274001 A274002 A274003 * A274005 A274006 A274007

Keyword

nonn

Author

Alisa Ediger, Jun 06 2016

Status

approved