A063178 Hexagonal spiral sequence: sequence is written as a hexagonal spiral around a 'dummy' center, each entry is the sum of the row in the previous direction containing the previous entry.

1, 1, 2, 3, 5, 8, 10, 23, 33, 42, 98, 110, 250, 286, 646, 749, 1681, 1939, 2059, 6428, 7097, 15584, 17556, 19279, 59516, 66042, 68211, 213048, 230854, 246724, 758837, 825525, 885790, 2716876, 2949411, 3164398, 3234668, 12951143, 13783096

Offset

1,3

Links

Table of n, a(n) for n=1..39.

F.M. van Lamoen, Spiral recurrence.

Example

The spiral starts
                  749---646---286
                  /             \
                 /               \
              1681    5-----3    250
               /     /       \     \
              /     /         \     \
           1939    8     *     2    110
            /     /     /     /     /
           /     /     /     /     /
        2059   10     1-----1    98
           \     \               /
            \     \             /
           6428   23----33----42

Crossrefs

Cf. A062410, A063177.

Sequence in context: A004694 A309527 A023176 * A280205 A276731 A028891

Adjacent sequences: A063175 A063176 A063177 * A063179 A063180 A063181

Keyword

nonn,nice

Author

Floor van Lamoen, Jul 09 2001

Status

approved