A004435 Positive integers that are not the sum of 2 distinct square integers.

2, 3, 6, 7, 8, 11, 12, 14, 15, 18, 19, 21, 22, 23, 24, 27, 28, 30, 31, 32, 33, 35, 38, 39, 42, 43, 44, 46, 47, 48, 51, 54, 55, 56, 57, 59, 60, 62, 63, 66, 67, 69, 70, 71, 72, 75, 76, 77, 78, 79, 83, 84, 86, 87, 88, 91

Offset: 1

Author

N. J. A. Sloane

Keywords

• nonn

Comments

A025435(a(n)) = 0. - Reinhard Zumkeller, Dec 20 2013

Links

• T. D. Noe, Table of n, a(n) for n=1..1000
• Index entries for sequences related to sums of squares

Crossrefs

Cf. A001983 (complement).

Programs

Haskell

a004435 n = a004435_list !! (n-1)
a004435_list = [x | x <- [1..], a025435 x == 0]
-- Reinhard Zumkeller, Dec 20 2013

Mathematica

Select[Range[100], Reduce[0 <= i < j && # == i^2 + j^2, {i, j}, Integers] === False &] (* Jean-François Alcover, Aug 01 2018 *)