A256087 Non-palindromic balanced numbers in base 7.

364, 420, 476, 492, 532, 548, 604, 640, 660, 708, 728, 764, 820, 836, 876, 892, 948, 984, 1004, 1052, 1072, 1108, 1164, 1180, 1220, 1236, 1292, 1328, 1348, 1396, 1416, 1452, 1508, 1524, 1564, 1580, 1636, 1672, 1692, 1740, 1760, 1796, 1852, 1868, 1908, 1924, 1980

Offset

1,1

Comments

Here a number is called balanced if the sum of digits weighted by their arithmetic distance from the "center" is zero. Since palindromes (A029954) are trivially balanced, they are excluded here.

This is the base-7 variant of the decimal version A256075 invented by Eric Angelini. See there, and the base-2 version A256082, for further information and examples.

Links

Table of n, a(n) for n=1..47.

Prog

(PARI) is(n, b=7, d=digits(n, b), o=(#d+1)/2)=!(vector(#d, i, i-o)*d~)&&d!=Vecrev(d)

Crossrefs

Cf. A256082 - A256089, A256075, A256080, A029954.

Sequence in context: A098251 A115464 A004534 * A260837 A272359 A351541

Adjacent sequences: A256084 A256085 A256086 * A256088 A256089 A256090

Keyword

nonn,base

Author

M. F. Hasler, Mar 14 2015

Status

approved