A367727 a(n) is the numerator of (R(n) - 1)/(n + 1), where R(n) is the digit reversal of n.

-1, 0, 1, 1, 3, 2, 5, 3, 7, 4, 0, 5, 20, 15, 8, 25, 60, 35, 80, 9, 1, 1, 21, 31, 41, 51, 61, 71, 81, 91, 2, 3, 2, 16, 6, 13, 62, 36, 82, 23, 3, 13, 23, 3, 43, 53, 63, 73, 83, 93, 4, 7, 24, 17, 4, 27, 64, 37, 84, 47, 5, 15, 25, 35, 9, 5, 65, 75, 85, 19, 6, 2, 26

Offset: 0

Author

Stefano Spezia, Nov 28 2023

Keywords

• sign
• base
• easy
• frac
• look

Links

• Stefano Spezia, Table of n, a(n) for n = 0..10000

Crossrefs

Cf. A004086, A367593, A367728 (denominator).

Programs

Mathematica

a[n_]:=Numerator[(FromDigits[Reverse[IntegerDigits[n]]]-1)/(n+1)]; Array[a,73,0]

PARI

a(n) = numerator((fromdigits(Vecrev(digits(n)))-1)/(n+1)); \\ Michel Marcus, Nov 28 2023