A182580 Position of first occurrence of n in A182576.

0, 1, 2, 5, 11, 27, 29, 46, 76, 167, 133, 348, 521, 1160, 1364, 3005, 3571, 9348, 9349, 20820, 24476, 64062, 64079, 123651, 167761, 439203, 439204, 1149850, 1149851, 3010348, 3010349, 7881195, 7881196, 20633238, 20633239, 54018520, 54018521, 141422323, 141422324

Offset: 0

Author

Alex Ratushnyak, May 05 2012

Keywords

• nonn

Comments

Conjecture: for k > 12, a(2k) = a(2k-1) + 1.

Examples

			First occurrence of 4 in A182576(n) has index 11, so a(4)=11.
		

Crossrefs

Cf. A182576.

Programs

C

#include  // GCC // ~880 secs
typedef unsigned long long U64;
U64 fibs[992], first[992], prpr=0, prev=1, current, n, sq;
long long ftop, fpos, terms;
int main(int argc, char **argv)
{
    for (ftop=0; ftop<900; ++ftop) {
      fibs[ftop] = current = prpr+prev;
      if (current0 && fpos>=0; ++terms, sq-=fibs[fpos], --fpos) {
                while (fibs[fpos]>sq && fpos>0) --fpos;
        }
        if (sq>0) { printf("Error!"); exit(1); }
        if (first[terms]==0)
            first[terms]=n, printf("%2llu %llu\n",terms,n);
    }
    for (n=0; n