A003247 Complement of A003248.

1, 2, 3, 4, 6, 7, 8, 9, 10, 11, 12, 13, 15, 16, 17, 18, 19, 21, 22, 23, 24, 25, 26, 27, 28, 30, 31, 32, 33, 34, 36, 37, 38, 40, 41, 42, 43, 44, 46, 47, 48, 49, 50, 51, 52, 53, 55, 56, 57, 58, 59, 61, 62, 63, 64, 65, 66, 67, 68, 70, 71, 72, 73, 74, 75, 76, 77

Offset: 1

Author

N. J. A. Sloane

Keywords

• nonn

Comments

Numbers k such that A003234(k) equals the image of some x by A000201(A001950()) (see 1.20 p. 339 of Carlitz link). - Michel Marcus, Feb 02 2014

This is the function named t in [Carlitz]. - Eric M. Schmidt, Aug 14 2014

References

• N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).

Links

• L. Carlitz, R. Scoville and T. Vaughan, Some arithmetic functions related to Fibonacci numbers, Fib. Quart., 11 (1973), 337-386.
• A. M. Odlyzko, Letters to N. J. A. Sloane Feb 1974.

Programs

PARI

A000201(n) = floor(n*(sqrt(5)+1)/2);
A001950(n) = floor(n*(sqrt(5)+3)/2);
A003231(n) = floor(n*(sqrt(5)+5)/2);
is003234(n) = A003231(A001950(n)) == A001950(A003231(n)) - 1;
lista(nn) = {vab = vector(nn, i, A000201(A001950(i))); v003234 = select(n->is003234(n), vector(nn, i, i)); for (n=1, #v003234, if (vecsearch(vab, v003234[n]), print1(n, ", ")););} \\ Michel Marcus, Feb 02 2014

Extensions

More terms from Michel Marcus, Feb 02 2014

New definition from Eric M. Schmidt, Aug 14 2014