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Smallest self-descriptive number in base b, or -1 if no such number exists.
1

%I #3 Jul 23 2016 10:23:52

%S -1,-1,100,1425,-1,389305,8946176,225331713,6210001000,186492227801,

%T 6073061476032,213404945384449,8054585122464440,325144322753909625,

%U 13983676842985394176

%N Smallest self-descriptive number in base b, or -1 if no such number exists.

%C 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.

%e 1210_4 = 100, 21200_5 = 1425, 3211000_7 = 389305,

%e 42101000_8 = 8946176, 521001000_9 = 225331713, 6210001000_10,

%e 72100001000_11 = 186492227801, 821000001000_12 = 6073061476032,

%e 9210000001000_13 = 213404945384449, (10)2100000001000_14 =

%e 8054585122464440, (11)21000000001000_15 = 325144322753909625,

%e (12)21000000001000_16 = 13983676842985394176, etc.

%Y Very similar to A108551.

%K sign,base,more

%O 2,3

%A _N. J. A. Sloane_, Jul 23 2016, following an email from Amarnath Krishnamurthy [_Amarnath Murthy_] and in addition using data from A108551.