login

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).

A044373
Numbers n such that string 4,1 occurs in the base 10 representation of n but not of n-1.
1
41, 141, 241, 341, 410, 441, 541, 641, 741, 841, 941, 1041, 1141, 1241, 1341, 1410, 1441, 1541, 1641, 1741, 1841, 1941, 2041, 2141, 2241, 2341, 2410, 2441, 2541, 2641, 2741, 2841, 2941, 3041, 3141, 3241, 3341, 3410, 3441
OFFSET
1,1
MATHEMATICA
SequencePosition[Table[If[SequenceCount[IntegerDigits[n], {4, 1}]>0, 1, 0], {n, 3500}], {0, 1}][[;; , 2]] (* Harvey P. Dale, Aug 27 2024 *)
CROSSREFS
Sequence in context: A253682 A297398 A142449 * A044754 A254898 A217087
KEYWORD
nonn,base
STATUS
approved