The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A014133 Sum of a square and a triangular number. 5
 0, 1, 2, 3, 4, 5, 6, 7, 9, 10, 11, 12, 14, 15, 16, 17, 19, 21, 22, 24, 25, 26, 28, 29, 30, 31, 32, 35, 36, 37, 39, 40, 42, 44, 45, 46, 49, 50, 51, 52, 53, 54, 55, 56, 57, 59, 61, 64, 65, 66, 67, 70, 71, 72, 74, 75, 77, 78, 79, 80, 81, 82, 84, 85, 87, 91 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,3 LINKS Harvey P. Dale, Table of n, a(n) for n = 0..1000 FORMULA {k: A101428(k) > 0} .- R. J. Mathar, Apr 28 2020 MAPLE isA014133 := proc(n)     local c, t ;     for c from 0 do         t := c*(c+1)/2 ;         if t > n then             return false;         end if;         if issqr(n-t) then             return true;         end if;     end do: end proc: for n from 0 to 100 do     if isA014133(n) then         printf("%d, ", n) ;     end if; end do: # R. J. Mathar, Oct 11 2014 MATHEMATICA With[{nn=20}, Select[Union[Flatten[Outer[Plus, Range[0, nn]^2, Accumulate[ Range[ 0, nn]]]]], #<=(nn(nn+1))/2&]] (* Harvey P. Dale, Dec 29 2019 *) CROSSREFS Cf. A014134 (complement). Sequence in context: A214879 A187226 A026470 * A070115 A073571 A328242 Adjacent sequences:  A014130 A014131 A014132 * A014134 A014135 A014136 KEYWORD nonn AUTHOR STATUS approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified June 16 04:56 EDT 2021. Contains 345056 sequences. (Running on oeis4.)