A284812 - OEIS

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A284812

Numbers n such that n' = d_1^1 + d_2^2 + ... + d_k^k where d_1, d_2, ..., d_k are the digits of n, with MSD(n) = d_1 and LSD(n) = d_k, and n' is the arithmetic derivative of n.

4, 34, 78, 47863, 67277, 472621, 525038, 5576423, 7541551, 12485411, 13600033, 41777431, 48288701, 64979641, 97807441, 136272511, 153060223, 201916441, 214821521, 225015223

(list; graph; refs; listen; history; text; internal format)

OFFSET

1,1

LINKS

Table of n, a(n) for n=1..20.

EXAMPLE

47863' = 2104 = 4^1 + 7^2 + 8^3 + 6^4 + 3^5.

MAPLE

with(numtheory): P:=proc(q) local a, k, n, p; for n from 1 to q do a:=convert(n, base, 10);

if add(a[k]^(nops(a)-k+1), k=1..nops(a))=n*add(op(2, p)/op(1, p), p=ifactors(n)[2])

then print(n); fi; od; end: P(10^9);

CROSSREFS