OEIS A005195

URI: https://gptkb.org/entity/OEIS_A005195
GPTKB entity
Statements (29)
Predicate Object
gptkbp:instanceOf gptkb:integer_sequence
gptkbp:author gptkb:N._J._A._Sloane
gptkbp:citation gptkb:OEIS_A001844
gptkb:OEIS_A003215
gptkb:OEIS_A006005
Handbook of Integer Sequences, N.J.A. Sloane, 1973 (includes this sequence as M2282)
gptkbp:describes Centered hexagonal numbers are figurate numbers that represent a hexagon with a dot in the center and all other dots surrounding the center in successive hexagonal layers.
gptkbp:eighth_term 169
gptkbp:fifthBook 61
gptkbp:first_terms 1
7
gptkbp:form a(n) = 2*n^2 - 2*n + 1 + n^2
a(n) = 3n(n-1) + 1
gptkbp:fourthPlace 37
gptkbp:hasKeyword nonn,easy,nice
gptkbp:link https://oeis.org/A005195
gptkbp:name gptkb:Centered_hexagonal_numbers
gptkbp:ninth_term 217
gptkbp:OEIS A005195
gptkbp:offset 1,2
gptkbp:recurrence a(n) = a(n-1) + 6*(n-1), a(1)=1
gptkbp:sequence 1, 7, 19, 37, 61, 91, 127, 169, 217, 271, ...
gptkbp:seventhBook 127
gptkbp:sixthBook 91
gptkbp:tenth_term 271
gptkbp:thirdPlace 19
gptkbp:bfsParent gptkb:OEIS_A000372
gptkbp:bfsLayer 6
https://www.w3.org/2000/01/rdf-schema#label OEIS A005195