The OEIS is supported by the many generous donors to the OEIS Foundation.

 Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 59th year, we have over 358,000 sequences, and we’ve crossed 10,300 citations (which often say “discovered thanks to the OEIS”). Other ways to Give
 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A232395 (ceiling(sqrt(n^3 + n^2 + n + 1)))^2 - (n^3 + n^2 + n + 1). 3
 0, 0, 1, 9, 15, 13, 30, 0, 40, 21, 45, 57, 51, 21, 70, 105, 120, 109, 66, 156, 43, 77, 81, 49, 216, 108, 217, 9, 36, 21, 293, 192, 31, 189, 309, 385, 411, 381, 289, 129, 408, 112, 281, 396, 451, 440, 357, 196, 624, 309, 613, 120, 276, 360, 366, 288, 120, 725 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,4 COMMENTS a(n)=0, iff 1 + n + n^2 + n^3 is a perfect square. For example, a(7)=0 and we have 1 + 7 + 7^2 + 7^3 = 20^2. a(n) = Difference between smallest square >= (n^3 + n^2 + n + 1) and (n^3 + n^2 + n + 1) - Antti Karttunen, Nov 27 2013 LINKS Ivan Panchenko, Table of n, a(n) for n = 0..1000 FORMULA Contribution from Antti Karttunen, Nov 27 2013: (Start) a(n) = A000290(⌈sqrt(A053698(n))⌉) - A053698(n). Where ⌈x⌉ stands for ceiling(x). This further reduces as: a(n) = A000290(A135034(A053698(n))) - A053698(n). a(n) = A048761(A053698(n)) - A053698(n). a(n) = A068527(A053698(n)). (End) PROG (PARI) a(n) = ceil(sqrt(n^3+n^2+n+1))^2 - (n^3+n^2+n+1); \\ Michel Marcus, Nov 23 2013 CROSSREFS Cf. A053698, A068527. Sequence in context: A073920 A130119 A346609 * A184048 A284128 A058957 Adjacent sequences: A232392 A232393 A232394 * A232396 A232397 A232398 KEYWORD nonn AUTHOR Vladimir Shevelev, Nov 23 2013 EXTENSIONS More terms from Peter J. C. Moses STATUS approved

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

Last modified December 2 12:34 EST 2022. Contains 358496 sequences. (Running on oeis4.)