A216388 Number of values of k for which sigma(k)-k is a permutation of decimal digits of k, for k < 10^n.

1, 2, 5, 15, 55, 270, 1494, 8081, 3395709, 53903207

Offset

1,2

Links

Table of n, a(n) for n=1..10.

Formula

a(n) = # { k in A085844 | k < 10^n }. - M. F. Hasler, Feb 24 2014

Example

a(3) = 5 because the values of k satisfying the condition for k < 10^3 are {6, 28, 411, 496, 604}. - V. Raman, Feb 17 2014

Prog

(PARI) a(n)=sum(k=1, 10^n, vecsort(digits(k)) == vecsort(digits(sigma(k)-k))) \\ V. Raman, Feb 17 2014, based on edits by M. F. Hasler

Crossrefs

Cf. A085844, A001065.

Sequence in context: A363200 A137533 A121392 * A005976 A351158 A187981

Adjacent sequences: A216385 A216386 A216387 * A216389 A216390 A216391

Keyword

nonn,base,more

Author

V. Raman, Sep 06 2012

Extensions

a(9)-a(10) from Lars Blomberg, Jan 23 2016

Status

approved