A255968 Numbers n such that antisigma(n) contains n as a substring.

24, 57, 204, 411, 559, 2004, 2440, 3935, 6616, 8640, 20004, 34939, 55827, 61009, 64599, 79747, 87113, 87269, 96513, 481557, 621265, 647532, 702893, 704682, 797465, 2000004, 2385120

Offset

1,1

Comments

Any number of the form 20...04, with a number of consecutive zeros not equal to 6*k+4 (with k = 0, 1, 2, 3,...), appears to belong to the sequence.

Links

Table of n, a(n) for n=1..27.

Example

antisigma(24) = (24*25) / 2 - sigma(24) = 300 - 60 = 240 and 24 is a substring;
antisigma(57) = (57*58) / 2 - sigma(57) =  1653 - 80 = 1573 and 57 is a substring.

Maple

with(numtheory): P:=proc(q) local a, b, c, d, j, n;
for n from 1 to q do a:=n; b:=n*(n+1)/2-sigma(n); c:=ilog10(n)+1; d:=ilog10(b)+1;
for j from 1 to d-c+1 do if n=(b mod 10^c) then print(n); break; else b:=trunc(b/10);
fi; od; od; print(); end: P(10^9);

Crossrefs

Cf. A024816.

Sequence in context: A208086 A232937 A190104 * A211325 A290303 A044126

Adjacent sequences: A255965 A255966 A255967 * A255969 A255970 A255971

Keyword

nonn,base

Author

Paolo P. Lava, Mar 12 2015

Status

approved