OFFSET
2,3
COMMENTS
A self-descriptive number in base b has b digits, indexed by 0 ... b-1 and for all n, the n-th digit equals the number of n's in the number. In base 10 there is exactly one such number, 6210001000.
EXAMPLE
1210_4 = 100, 21200_5 = 1425, 3211000_7 = 389305,
42101000_8 = 8946176, 521001000_9 = 225331713, 6210001000_10,
72100001000_11 = 186492227801, 821000001000_12 = 6073061476032,
9210000001000_13 = 213404945384449, (10)2100000001000_14 =
8054585122464440, (11)21000000001000_15 = 325144322753909625,
(12)21000000001000_16 = 13983676842985394176, etc.
CROSSREFS
KEYWORD
sign,base,more
AUTHOR
N. J. A. Sloane, Jul 23 2016, following an email from Amarnath Krishnamurthy [Amarnath Murthy] and in addition using data from A108551.
STATUS
approved