A256363 Numbers that are multiple-digit narcissistic numbers in exactly four bases.

4901, 8450, 21125, 33125, 41405, 42050, 47125, 71825, 90625, 117325, 142805, 142885, 151250, 184093, 244205, 272000, 325125, 361250, 520625, 535717, 546325, 638450, 690625, 777925, 861125, 874225, 903125, 982125, 990125, 1035125, 1053405

Offset

1,1

Links

Table of n, a(n) for n=1..31.

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

Eric Weisstein's World of Mathematics, Narcissistic Number

Wikipedia, Narcissistic number

Example

a(1) = 4901 because this is the first number that is a multiple-digit narcissistic number in exactly four bases (75, 99, 186 and 4831).

Prog

(PARI) for(n=3, 1000000, 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==4, print1(n, ", ")))

Crossrefs

Cf. A005188.

Cf. A256359 (every number of bases).

Cf. A256360, A256361, A256362, A256364, A256365 (1, 2, 3, 5 and 6 bases).

Cf. A256459 (first occurrences).

Sequence in context: A321146 A374500 A107545 * A031568 A083607 A168028

Adjacent sequences: A256360 A256361 A256362 * A256364 A256365 A256366

Keyword

nonn,base

Author

Tim Johannes Ohrtmann, Mar 26 2015

Status

approved