A339541 a(n) = n + sod(n, sod(n, 10)), where sod(n,b) is the sum of base-b digits of n.

2, 3, 4, 5, 6, 7, 8, 9, 10, 20, 14, 14, 17, 20, 20, 20, 20, 20, 29, 22, 24, 26, 30, 28, 32, 31, 30, 38, 38, 32, 38, 36, 41, 44, 42, 40, 47, 46, 45, 44, 46, 44, 50, 53, 50, 56, 54, 52, 62, 52, 57, 56, 64, 60, 65, 62, 70, 68, 66, 65, 68, 75, 70, 74, 80, 77, 74, 84, 82, 74, 79, 80, 83, 88, 84, 92

Offset

1,1

Links

Robert Israel, Table of n, a(n) for n = 1..10000

Formula

a(n) = n + A138530(n, A007953(n)).

Example

a(15) = 15 + 5 = 20 because sod(15,10) = 6 and sod(15,6) = 5 (because 15 = 23_6).

Maple

sod:= proc(x, b) if b=1 then x else convert(convert(x, base, b), `+`) fi end proc:
f:= x -> x + sod(x, sod(x, 10)):
map(f, [$1..100]);

Crossrefs

Cf. A007953, A138530

Sequence in context: A210538 A247143 A257128 * A247808 A247807 A247804

Adjacent sequences: A339538 A339539 A339540 * A339542 A339543 A339544

Keyword

nonn,base

Author

Robert Israel, Dec 08 2020

Status

approved