A227179 After initial 0, integers from 0 to n(n-1) followed by integers from 0 to n(n+1) and so on.

0, 0, 0, 1, 2, 0, 1, 2, 3, 4, 5, 6, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30

Offset

0,5

Links

Antti Karttunen, Table of n, a(n) for n = 0..9951

Formula

a(n) = n - (1 + A006527(A227177(n)-1)).

Mathematica

Flatten[(Range[(#-2) (#-1)+1]-1&)[Range[7]]] (* Peter J. C. Moses, Jul 11 2013 *)

Prog

(Scheme): (define (A227179 n) (- n (+ 1 (A006527 (- (A227177 n) 1)))))
(Python)
from sympy import integer_nthroot
def A227179(n): return n-1-(f:=lambda x:x*(x**2+2))((m:=integer_nthroot(k:=3*n, 3)[0])-(k<=f(m)))//3 # Chai Wah Wu, Nov 07 2024

Crossrefs

Cf. A002378, A006527, A227177, A227181, A227182.

Sequence in context: A238794 A135317 A332663 * A115218 A023858 A011118

Adjacent sequences: A227176 A227177 A227178 * A227180 A227181 A227182

Keyword

nonn

Author

Antti Karttunen, Jul 03 2013

Status

approved