A022549 Sum of a square and a nonnegative cube.

0, 1, 2, 4, 5, 8, 9, 10, 12, 16, 17, 24, 25, 26, 27, 28, 31, 33, 36, 37, 43, 44, 49, 50, 52, 57, 63, 64, 65, 68, 72, 73, 76, 80, 81, 82, 89, 91, 100, 101, 108, 113, 121, 122, 125, 126, 127, 128, 129, 134, 141, 144, 145

Offset

1,3

Comments

It appears that there are no modular constraints on this sequence; i.e., every residue class of every integer has representatives here. - Franklin T. Adams-Watters, Dec 03 2009

A045634(a(n)) > 0. - Reinhard Zumkeller, Jul 17 2010

Links

R. Zumkeller, Table of n, a(n) for n = 1..10000 - Reinhard Zumkeller, Jul 17 2010

Mathematica

q=30; imax=q^2; Select[Union[Flatten[Table[x^2+y^3, {y, 0, q^(2/3)}, {x, 0, q}]]], #<=imax&] (* Vladimir Joseph Stephan Orlovsky, Apr 20 2011 *)

Prog

(PARI) is(n)=for(k=0, sqrtnint(n, 3), if(issquare(n-k^3), return(1))); 0 \\ Charles R Greathouse IV, Aug 24 2020
(PARI) list(lim)=my(v=List(), t); for(k=0, sqrtnint(lim\=1, 3), t=k^3; for(n=0, sqrtint(lim-t), listput(v, t+n^2))); Set(v) \\ Charles R Greathouse IV, Aug 24 2020

Crossrefs

Complement of A022550; A002760 and A179509 are subsequences.

Cf. A055394, A045634, A055393, A123291, A169618, A123364, A111925.

Sequence in context: A166110 A087815 A248893 * A045704 A368796 A351723

Adjacent sequences: A022546 A022547 A022548 * A022550 A022551 A022552

Keyword

nonn,easy

Author

N. J. A. Sloane.

Status

approved