A256459 Least number that is a multiple-digit narcissistic number in exactly n bases.

5, 17, 125, 4901, 274625, 36125

Offset

1,1

Links

Table of n, a(n) for n=1..6.

W. Schneider, Perfect Digital Invariants: Pluperfect Digital Invariants(PPDIs)

Eric Weisstein's World of Mathematics, Narcissistic Number

Wikipedia, Narcissistic number

Example

a(3) = 125 because this is the least number that is a multiple-digit narcissistic number in exactly three bases (12, 23 and 57).

Prog

(PARI) b=0; until(b==6, b++; n=2; until(k==b, n++; k=0; for(z=2, n, y=n; j=0; L=List(); until(y==0, x=y%z; j++; listinsert(L, x, j); while(!((y%z)==0), y--); y=y/z); t=0; for(p=1, j, t+=L[p]^j); if(n==t, k++)); if(k==b, print1(n, " "))))

Crossrefs

Cf. A005188.

Cf. A256359 (every number of bases).

Cf. A256360, A256361, A256362, A256363, A256364, A256365 (1 to 6 bases).

Sequence in context: A012174 A202038 A012259 * A113936 A365295 A012263

Adjacent sequences: A256456 A256457 A256458 * A256460 A256461 A256462

Keyword

nonn,base,hard,more

Author

Tim Johannes Ohrtmann, Mar 30 2015

Status

approved