A283471 Numbers n > 2 such that A004001(A004001(n-1)) = A004001(n-A004001(n-1)).

3, 4, 6, 7, 8, 10, 13, 14, 15, 16, 18, 28, 29, 30, 31, 32, 34, 59, 60, 61, 62, 63, 64, 66, 122, 123, 124, 125, 126, 127, 128, 130, 249, 250, 251, 252, 253, 254, 255, 256, 258, 504, 505, 506, 507, 508, 509, 510, 511, 512, 514, 1015, 1016, 1017, 1018, 1019, 1020, 1021, 1022, 1023, 1024, 1026, 2038, 2039, 2040, 2041, 2042, 2043, 2044, 2045

Offset

1,1

Comments

Equally, numbers n > 2 for which A004001(A004001(n-1)) = A004001(A080677(n-1)).

Links

Antti Karttunen, Table of n, a(n) for n = 1..185

Mathematica

a[n_] := a[n] = If[n <= 2, 1, a[a[n - 1]] + a[n - a[n - 1]]]; Select[Range[3, 2^11], Function[n, a[#] == a[n - #] &@ a[n - 1]]] (* Michael De Vlieger, Mar 18 2017, after Robert G. Wilson v at A004001 *)

Prog

(Scheme, with Antti Karttunen's IntSeq-library)
(define A283471 (ZERO-POS 1 1 A283470))
(define A283471 (MATCHING-POS 1 3 (lambda (n) (= (A004001 (A004001 (- n 1))) (A004001 (- n (A004001 (- n 1))))))))

Crossrefs

Positions of zeros in A283468 and A283470.

Cf. A004001, A080677, A283473.

Subsequence of A283482.

Sequence in context: A105454 A364006 A283482 * A127260 A089530 A201820

Adjacent sequences: A283468 A283469 A283470 * A283472 A283473 A283474

Keyword

nonn

Author

Antti Karttunen, Mar 18 2017

Status

approved